Casting sand used in a mold is reutilized sometimes by milling the mold (mold disassembly) into sand and then reclaiming the recovered sand. As the process for reclaiming recovered sand, various processes such as a wet reclaiming process, a heating reclaiming process and a dry reclaiming process have been proposed for a long time (for example, ' Igata Chuzo Hou' (Mold Casting Process), 4th edition, November 18, 1996, Japan Association of Casting Technology, pp. 327-330) and practically used. JP-A 6-154941 discloses a process for reclaiming casting sand, which contains subjecting heat treatment to predetermined recovered sand and then subjecting the sand to dry grinding treatment. 1 is a schematic cross-section showing one example of a casting sand-reclaiming apparatus that can be used in dry grinding treatment of recovered sand in the presence of additive (A); • FIG. 2 is a schematic cross-section showing one example of a casting sand-reclaiming apparatus that can be used in grinding treatment with water in the present invention; • FIG.

Oct 26, 2017. The floor beneath your feet is completely free. Have you ever dropped right down to the floor at present and knocked out 25 pushups? Have you performed this 4 instances in the present day, 4 Manual Treadmill Lincoln times yesterday, and each day for the past 30 days? Have you labored the most. E manuale Kruss tensiometer k100 manual transmission New zone 40 wireless gaming manual Rupert neve 5088 manual dexterity Alcatel one touch 292 manual arts Toyota camry manual transmission diagram Virtual dj manually set bpm serato Samsung galaxy duos s7562 user manual Shaw box 700 manual.

3 is an enlarged schematic cross-section showing a part of a casting sand-reclaiming apparatus that can be used in grinding treatment with water in the present invention; and • FIG. 4 is a flowchart showing procedures in the Examples and Comparative Examples, wherein 21 is the body of equipment; 22, a lower stirring tank; 23, an upper classification tank; 24, a blast room; 25, a blast opening; 26, a fluidized bed, and 220, recovered sand. Detailed Description of the Invention•. In conventional arts, the wet reclaiming process requires a wastewater treatment equipment and thus necessitates the cost of equipment and increases the reclamation cost. Further, sand should be dried after reclamation treatment. The heating reclaiming process requires combustion facilities and air-cooling facilities and thus necessitates tremendous energy costs, and exhaust gas treatment should be performed. In the dry reclaiming process, a method of utilizing centrifugal force to give friction among sand particles thereby removing a binder etc.

Adhering to the surfaces of the sand particles is prevailing at present. In this method, however, when the efficiency of reclamation is to be increased, the yield is reduced due to destruction and pulverization of sand, and power source unit per tone of recovered sand is also increased. The artificial ceramic sand does not include naturally occurring casting sand such as silica sand, zircon sand or chromite sand, but casting sand obtained by artificially regulating metal oxide components in sand and then melting or sintering the sand. From the viewpoint of high resistance to fracture and further reduction in wastes, casting sand containing not less than 80 wt% Al 2O 3 and SiO 2 in total at an Al 2O 3/SiO 2 weight ratio of 1 to 15 is preferable. The artificial ceramic sand preferably has a crystal phase of at least one of mullite, α-alumina and γ-alumina. Such spherical casting sand can be produced for example by a method of granulating refractory raw slurry by spray drying to make it spherical followed by sintering, a method of melting a refractory raw material and jetting the material out with air from nozzles to make it spherical, or a method of dispersing refractory particles in a carrier gas and melting the particles in flame to make them spherical; for example, the spherical casting sand can be produced by methods shown in JP-A 61-63333, JP-A 2003-251434, JP-A 2005-193267, and JP-A 2004-202577.

The alkali phenol resin includes phenol resins obtained for example by reacting a phenol such as phenol, cresol, resorcinol, bisphenol A or another substituted phenol as a starting material with an aldehyde compound in the presence of an alkali catalyst. The alkali catalyst includes alkali metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide, alkaline earth metal hydroxides such as calcium hydroxide, magnesium hydroxide and beryllium hydroxide, amine compounds, and mixture thereof.

Generally, the number of moles of the alkali catalyst is 0.05- to 4-fold, more preferably 0.1- to 3-fold, based on the number of moles of the phenol. The surface tension of the additive (A)at 25°C is preferably 15 to 35 mN/m, more preferably 15 to 33 mN/m, from the viewpoint of preventing dust, generating upon the grinding treatment, from adhering on reclaimed sand. Further, the boiling point of the additive (A) at 1 atmospheric pressure is preferably 150 to 400°C, more preferably 165°C to 400°C, from the viewpoint that they may not be lost more quickly than dust in collection of dust. The additive (A)contains a material having a decomposition point of 400°C or less and being liquid at least at 150°C.

The amount of the additive (A) per 100 parts by weight of recovered sand during the grinding treatment is preferably 0.001 part by weight or more from the viewpoint of exhibiting an effect of removing residual resin or 0.2 part by weight or less from an economic viewpoint and the viewpoint of saturation of the effect, and thus the additive (A) is allowed to be present in a ratio of preferably 0.001 to 0.2 part by weight, more preferably 0.005 to 0.1 part by weight, even more preferably 0.01 to 0.05 part by weight, relative to 100 parts by weight of recovered sand. In the present invention, the grinding treatment of recovered sand is conducted preferably plural times, wherein the grinding treatment is conducted at least once in the presence of the additive (A), preferably in the presence of a silicone oil. That is, the production process of the present invention is a process wherein the grinding treatment of recovered sand is conducted at least once, and the grinding treatment is conducted at least once in the presence of the additive (A), preferably in the presence of a silicone oil. When grinding is conducted plural times, first grinding may be conducted by adding the additive (A), preferably a silicone oil, to recovered sand prior to a step of removing residual organic components from recovered sand by grinding treatment (including grinding treatment with water described later), however from the viewpoint of the effect of separating and removing impurities, it is preferable that the grinding treatment is conducted after addition of the additive (A), preferably a silicone oil, to recovered sand at the time of grinding treatment.

The added amount in the grinding treatment is preferably 0.001 part by weight or more to 100 parts by weight of reclaimed sand from the viewpoint of removing residual resin. Then the added amount is preferably 0.2 part by weight or less from an economic viewpoint and from the viewpoint of saturation of the effect. That is, the added amount is preferably 0.001 to 0.2 part by weight, more preferably 0.005 to 0.1 part by weight, even more preferably 0.01 to 0.05 part by weight. In this case, the term 'at the time of grinding treatment' refers to time between a point just before the grinding and during grinding.

It is more preferable that sand after subjected once or more to grinding treatment is subjected to grinding treatment by adding the additive (A), preferably a silicone oil, to the sand. The method of adding the additive (A) to recovered sand or to recovered sand after grinding treatment may be either a continuous or batch method. A method of spraying the additive (A) or a method of adding the additive (A) quantitatively through nozzles may be used. The additive and recovered sand may be mixed in a special mixing machine, however because they are mixed in a reclaiming machine, use of a special mixing machine is not particularly necessary.

Alternatively, a reclaiming machine in which grinding treatment is conducted in the presence of the additive (A) may be provided with an adding means such as a spray and nozzles through which the additive (A) is added. Depending on the case, the addition time can be controlled with a sequence or the like to regulate the addition time appropriately. The grinding treatment in step (I) can be conducted in accordance with grinding treatment in the conventional method of reclaiming casting sand, preferably in the dry process. Preferably, the grinding treatment in the presence of the additive (A) is carried out simultaneously with removal of releasable components particularly releasable organic components from sand. That is, the removal of releasable organic components (discharge of releasable organic components from the grinding system) is preferably conducted in step (I) of grinding treatment of recovered sand in the presence of the additive (A).

Releasable organic components allowed to hardly adhere to sand by the present invention can be efficiently removed from the surface of the sand and can simultaneously be separated and removed from sand by dust collection. The removal of releasable organic components can be conducted using an apparatus provided with a means of dust collection. Such an apparatus includes Hybrid Sand Master manufactured by Nippon Chuzo Co., Ltd. And Sand Fresher manufactured by Casting Machine Kiyota, and these apparatuses are more preferably used.

The process of the present invention preferably contains both step (Ia) where the grinding treatment of recovered sand is conducted once or more and step (Ib) where the sand after step (Ia) is subjected to grinding treatment by adding the additive (A) and simultaneously releasable organic components are removed. Cara Install John The Ripper Di Windows Phone. Step (Ia) is grinding treatment in substantially the absence of the additive (A) and can be carried out with the jetting stream type apparatus, the vertical axis rotation type apparatus, the horizontal axis rotation type apparatus or the vibration type apparatus. The grinding treatment in step (Ib) is a dry grinding treatment. This can be carried out by a known method to recovered sand to which the additive (A) have been added after the grinding treatment of step (Ia). A fluidized bed-type dry grinding apparatus, provided with a rotating member for grinding inside of the fluidized tank, is preferably used to remove effectively residual organic components being easily removable by the grinding treatment of step (Ia).

One example of this treatment is described by reference to the drawings. 1 is a schematic cross-section of a casting sand-reclaiming apparatus that can be used in dry grinding treatment in step (Ib) in the present invention, wherein 21 is the body of equipment. The body 21 is angular and is formed into a two-stage structure composed of 2 lower and upper parts that are a lower stirring tank 22 and an upper classification tank 23. 24 is a blast room formed at the bottom of the stirring tank 22, 25 is a blast opening, and 26 is a fluidized bed. The fluidized bed 26 is provided with a large number of convex protrusions having a plurality of vent holes formed in the side thereof. 27 and 28 are an inlet tube and a discharge tube respectively, which are arranged in the wall at opposed positions of the stirring tank 22, and 29 is a see-through window.

Both the inlet tube 27 and outlet tube 28 are arranged aslant in the wall at opposed positions of the stirring tank 22, and although not showing in detail, the openings of the inlet and outlet tubes, which are arranged on the same plane as that of the side wall, can be adjustably opened and closed by manual operation. 210 is a drive axis, 211 is left and right bearings, and 212 is a rotor. The bearings 211 are attached to the wall at both side of the stirring tank 22 and maintain the drive axis 210 in halfway height in the horizontal direction. 216 is a regulation plate, 217 is an exhaust opening, and 220 is recovered sand to which the additive (A) was added after grinding treatment in step (Ia). In the apparatus in FIG. 1, the sand to which the additive (A) was added after grinding in step (Ia) is introduced through the inlet tube 27.

Air from a blower is blown from the blast opening 25 through the fluidized bed 26 into the stirring tank 22, to fluidize the sand. The fluidized sand is ground both against the rotor 212 driven by a driving source, arranged in the stirring tank 22, and having a rough surface inclined toward the rotating face and against sand accumulated by centrifugal force in the vicinity of the swaying plate, thereby releasing materials adhering to the sand. The released adhering materials (released organic components etc.) are separated from the sand in a classification tank 23 provided with dust collection openings which communicate, via the regulation plate 216, with the upper part of the stirring tank 22.

After treatment for a predetermined time, the reclaimed casting sand is discharged through the outlet tube 28 (discharge opening). In the present invention, it is preferable that after 0.5 to 20 parts by weight of water are added to 100 parts by weight of recovered sand, grinding treatment (hereinafter referred to grinding treatment with water) is conducted. The difference between this grinding treatment with water and the conventional wet reclaiming process is that in the wet reclaiming process, recovered sand is reclaimed in a slurry state, that is, in a state of sand filled with water in voids in a particle layer thereof, while in the grinding treatment with water, recovered sand in a state ranging from a funicular region to capillary region, that is, a state of sand with water occurring in voids in a particle layer thereof but not occurring as a complete continuous layer.

When the amount of water herein is 0.5 part by weight or more relative to 100 parts by weight of recovered sand, residual organic components in the recovered sand can be easily and efficiently removed. When the amount of water is 20 parts by weight or less relative to 100 parts by weight of recovered sand, a sewage-treatment apparatus or excessive drying can be easily made unnecessary. This process uses a small amount of water and thus does not necessitate tremendous drying facilities and sewage-treatment apparatus as in the wet reclaiming process, and can give stronger load to sand than by the grinding treatment of sand in a slurry state.

Further, this process, as compared with the process of mechanically treating the surface of sand, can easily produce casting sand from which residual organic components were efficiently removed. It is estimated that by adding a small amount of water to recovered sand during grinding treatment, residual resin components strongly adhering to the sand is made easily removable, and by step (I) of grinding treatment in the presence of the additive (A), the residual organic components once removed can be prevented from adhering again to the surface of the sand, and as a result, the residual organic components in the recovered sand can be efficiently removed. In the present invention, the grinding treatment with water (grinding treatment in the presence of a predetermined amount of water) may be conducted at any stage in the process for producing reclaimed casting sand. When the grinding treatment of recovered sand is conducted plural times, the grinding treatment with water may be conducted at least once. That is, in the production process of the present invention, the grinding treatment of recovered sand may be conducted in the presence of a predetermined amount of water.

For example, the grinding treatment with water may be conducted simultaneously with step (I); that is, grinding treatment in the presence of the additive (A) may be conducted by adding water. Alternatively, the process of the present invention may be provided with the grinding treatment with water, separately from step (I), that is, separately from grinding treatment in the presence of the additive (A), and when the process has the steps (Ia) and (Ib) as described above, the grinding treatment with water may be conducted in either of the steps. Preferably, the grinding treatment with water is conducted in step (Ia), and then step (Ib), that is, the grinding treatment in the presence of the additive (A) is conducted (preferably in substantially the absence of water). When the step of grinding treatment with water is arranged separately different from step (I) or conducted in step (Ia), the grinding treatment is conducted preferably in substantially the absence of the additive (A). The process in the present invention may contain both the step of grinding treatment with water and step (I) of dry grinding treatment in the presence of the additive (A) (grinding treatment in substantially the absence of water).

That is, after the grinding treatment of recovered sand is conducted by adding 0.5 to 20 parts by weight of water to 100 parts by weight of the recovered sand, the dry grinding treatment can be conducted in the presence of the additive (A). When step (I) is provided with the steps (Ia) and (Ib) as described above, step (Ia) of grinding treatment with water added in an amount of 0.5 to 20 parts by weight to 100 parts by weight of recovered sand can be carried out as step (I). Accordingly, the method and apparatus for the grinding treatment with water described later are preferably those adapted to carry out step (Ia). A part of step (Ia) can be carried out as grinding treatment with water, and the order in this case is not limited.

The step of grinding treatment with water may be conducted either by introducing recovered sand to which water was added, into the grinding apparatus, or by introducing recovered sand into the grinding apparatus and simultaneously sprinkling water by spraying or the like. From the viewpoint of easily fluidizing the sand to which water was added, the grinding treatment with water in the present invention is carried out preferably by the grinding method using an apparatus of vertical axis rotation type, horizontal axis rotation type or vibration type, more preferably by the grinding method using an apparatus of vertical axis rotation type. Step (I) of grinding treatment in the presence of the additive (A) in the present invention can be carried out for example by subjecting recovered sand to the grinding treatment as described above. In the present invention, step (I) is conducted preferably in substantially the absence of water. With the term 'in substantially the absence of water' it is meant that the amount of water in sand to be subjected to the dry grinding treatment is preferably 0.2% by weight or less, more preferably 0.1% by weight or less, from the viewpoint of efficient removal of residual resin components in the dry grinding treatment. Accordingly, when the process contains the grinding treatment with water, the sand in which the amount of water was reduced preferably to this range is used in step (I). 2 shows one example of an apparatus suitable for the grinding treatment with water in the present invention, which is a vertical axis rotation type grinding apparatus.

The apparatus in FIG. When the grinding treatment with water is conducted in a certain time, the effect of reclamation treatment is generally increased. From the viewpoint of attaining an excellent reclamation effect, it is preferable that in the apparatus in FIG. 2 for example, the time in which the recovered sand 4 is retained in the space between the rotation drum 2 and the circular body 3 and subjected to grinding treatment, that is, retention time from when the recovered sand is retained till when the sand is discharged, is appropriately determined. In the apparatus in FIG. 2, the retention time can be regulated depending on the length of the gap formed between the upper circumference of the rotation drum and the circular body, the depth of the circular body, and the rate of introduction of recovered sand.

From this viewpoint, the upper circumference of the rotation drum 2 and the circular body 3 in the vertical axis rotation type apparatus form the gap 6 having a length that is 5- to 50-times, particularly 10- to 25-times the average particle size of the recovered sand 4 ( FIG. 3), and specifically the length of the gap is preferably 1 to 15 mm, more preferably 1.5 to 6 mm, even more preferably 1.5 to 4 mm. Generally, the average particle size of the recovered sand is about 75 to 600 µm.

This average particle size of the recovered sand is obtained as a particle size (median size) at which mass standard cumulative fraction reaches 0.5, according to a method described in the expression (Z 8819-1) of particle-size measurement result in JIS, on the basis of the result of particle-size distribution of recovered sand grains measured according to the test method (Z 2601) for particle-size distribution of casting sand in JIS. The rate of introduction of recovered sand is preferably 1 to 10 t/hr, more preferably 1.5 to 5 t/hr. When these conditions are used, the number of rotations of the rotation drum is preferably in the range as described above. For increasing the efficiency of grinding treatment in the grinding treatment with water, the position for introducing recovered sand or water is preferably regulated. In the vertical axis rotation type grinding apparatus, water or water and recovered sand are introduced preferably toward the center of the rotation drum 2 in the vertical axis rotation type grinding apparatus, that is, in the vicinity of the rotation axis. The region 'in the vicinity of the rotation axis', though varying depending on the size of the rotation drum, is preferably between the rotation axis and a position apart by (rotation drum diameter/4) from the axis, more preferably between the rotation axis and a position apart by (rotation drum diameter/5) from the axis.

The reclaimed casting sand obtained by the process of the present invention is used in production of a mold. The process for producing a mold is not particularly limited as long as the reclaimed casting sand obtained by the process of the present invention is used to produce a mold. This process is specifically a process for producing a mold which has hardening the reclaimed sand with an organic binder. The organic binder includes an alkali phenol resin, furan resin, thermosetting phenol resin (shell mold), and urethane resin, and a mold can be produced using the organic binder in its corresponding hardening method known in the art. Preferably, the organic binders are added in an amount of usually 0.05 to 10 parts by weight based on 100 parts by weight of the reclaimed sand.

The conventionally known silane coupling, additives etc. May also be used. The process for producing a mold according to the present invention is applied preferably to a mold obtained by hardening the binder with an organic ester compound.

0.30 part by weight of a hardening agent for alkali phenol resin (Kao Step KC-130 manufactured by Kao-Quaker Co., Ltd.) and 1.2 parts by weight of an alkali phenol resin (Kao Step S-660 manufactured by Kao-Quaker Co., Ltd.) were added to 100 parts by weight of spherical artificial ceramic casting sand with a sphericity of 0.99 containing 94 wt% Al 2O 3 and SiO 2 in total at an Al 2O 3/SiO 2 ratio (weight ratio) of 1.9 (the balance: TiO 2, 2.9% by weight; Fe 2O 3, 1.3% by weight; and very small amounts of CaO, MgO, Na 2O and K 2O). The mixture was stirred and formed into a mold having a sand/metal ratio of 4.

A cast iron melt (FC200) at 1400°C was poured into this mold and then cooled, and the mold was treated with a crusher to give recovered sand. The average particle size of the recovered sand was 200 µm. 0.1 part by weight of dimethyl silicone oil (KF96-10CS manufactured by Shin-Etsu Chemical Co. Ltd.) was added to, and mixed with, 100 parts of the recovered sand which was then subjected 4 times to dry grinding treatment with a rotating drum at a rotation number of 2450 rpm, at a sand feed rate of 3.1 t/hr, in a general vertical axis rotation type grinding apparatus (Rotary Reclaimer M, manufactured by Nippon Chuzo Co., Ltd.) to give reclaimed sand (the dimethyl silicone oil was added only once in the first grinding treatment). Analytical values of the recovered sand and reclaimed sand and results of a casting strength test are shown in Table 1. LOI, the degree of removal of LOI, and mold strength were evaluated by the following methods.

(1) LOI and the degree of removal of LOI removal•. A mold obtained by adding 1. 0 part by weight of an alkali phenol resin (Kao Step S-660 manufactured by Kao-Quaker Co. Download Opera Mini 7 Jar 320x240. , Ltd.) and 0.25 part by weight of a hardening agent for alkali phenol resin (Kao Step KC-140 manufactured by Kao-Quaker Co., Ltd.) to 100 parts by weight of the resulting reclaimed casting sand or recovered sand was measured one day after mixing for its compressive strength under the conditions of 25°C and 55% RH in accordance with JACT test method HM-1, with a strength testing machine AD-5000 manufactured by Shimadzu Corporation. Comparative Example 1•. After 0.02 part by weight of dimethyl silicone oil (KF96-10CS manufactured by Shin-Etsu Chemical Co.

Ltd.) was added to, and mixed with, 100 parts by weight of the reclaimed sand obtained in Comparative Example 1, 80 kg of the sand was introduced into a dry casting sand reclaiming apparatus (Hybrid Sand Master, type HSM1115, manufactured by Nippon Chuzo Co., Ltd.) provided with a fluidized bed as shown in FIG. 1, and then subjected to dry grinding treatment by batch treatment at a rotor rotation number of 2600 rpm for 30 min., to give reclaimed sand. When the dry grinding treatment was conducted, dust collection was carried out by floating releasable organic components from a fluidized bed. Analytical values (LOI and LOI removal degree) of the reclaimed sand and the strength of a mold were measured in the same manner as in Example 1. The results are shown in Table 1. Comparative Example 2•.

The recovered sand used in Example 1 was introduced at a sand feed rate of 2.7 t/hr into a high-speed rotation drum 2 such that 4 parts by weight of water was added to 100 parts by weight of the recovered sand (the amount of water in the recovered sand: 0.16% by weight) in a grinding apparatus capable of grinding treatment with water, having the structure shown in FIG. 2, followed by grinding treatment at a rotation number of 2542 rpm. The recovered sand was introduced toward the center of the high-speed rotation drum 2, and the corresponding water was also introduced toward the center of the high-speed rotation drum 2.

The gap 6 between the upper circumference of the high-speed rotation drum 2 and the circular body 3 in this grinding apparatus was 5 mm, and the depth of the circular body 3 was 100 mm (see FIG. 3), and the retention time of the sand during grinding treatment was 26 seconds. 80 kg of the resulting dried sand was introduced into a dry casting sand reclaiming apparatus (Hybrid Sand Master, type HSM1115, manufactured by Nippon Chuzo Co., Ltd.) provided with a layer as shown in FIG. 1, and then subjected to dry grinding treatment by batch treatment at a rotor rotation number of 2600 rpm for 12 min., to give reclaimed sand. When the dry grinding treatment was conducted, dust collection was carried out by floating releasable organic components from a fluidized layer.

Analytical values (LOI and LOI removal degree) of the reclaimed sand and the strength of a mold were measured in the same manner as in Example 1. The results are shown in Table 1.

The procedures in Examples 1 to 3 and Comparative Examples 1 to 2 are shown in the flowchart in FIG. From the results in Table 1, it can be seen that in the Examples as compared with the Comparative Examples, residual organic components can be efficiently removed by adding the silicone oil, and a mold using the same can exhibit significant strength. Because casting sand is repeatedly used, the process for producing reclaimed casting sand according to the present invention can be repeatedly used to significantly reduce the saturated reclaimed sand LOI. This leads not only to the reduction in the amount of gas generated from a mold by reducing the LOI, but also to the reduction in the amount of added resin by improving mold strength so that gas defects can be significantly reduced, and is thus beneficial to the art. Further, the present invention, as compared with conventional reclamation technology, can reduce the frequency of reclamation treatment, thus significantly reducing electric power and significantly reducing facility costs. Usually, mold strength is improved as residual organic components are decreased, however when recovered sand is ground for a long time or subjected to grinding too many times, there is a phenomenon that as shown by comparison between Comparative Examples 1 and 2, mold strength is decreased even if residual organic components are decreased. This is probably because residual organic components once released by grinding treatment are finely pulverized with sand and adhere again to the surface of the sand, and such adhering components have larger specific surface areas and are thus considered to exert a particularly harmful effect on hardening of a binder.

In the present invention, on the other hand, residual organic components are decreased and simultaneously mold strength is improved as shown in comparison between Examples 1 and 2. The reason for further improvement in mold strength by the present invention is not evident, and it is estimated that by the presence of silicone oil, residual organic components once released are prevented from adhering again to sand and are made easily removable with collected dust, so re-adhering residual organic components exerting a particular harmful influence on mold strength are reduced, thereby significantly improving mold strength. It can be seen that by adding silicone oil to the sand after the step of grinding with water, residual organic components can be efficiently removed in reclamation treatment in a short time in Example 3 as compared with Example 2, and a mold using the resulting reclaimed sand can exhibit significant strength. It can also be seen that it is not necessary that dry grinding treatment is repeated many times, thus making it unnecessary to introduce multistage facilities as the facilities and making reclamation treatment feasible with simple facilities. Examples 4 to 9 and Comparative Examples 3 to 5•. 0.30 part by weight of a hardening agent for alkali phenol resin (Kao Step KC-130 manufactured by Kao-Quaker Co., Ltd.) and 1.2 parts by weight of an alkali phenol resin (Kao Step S-660 manufactured by Kao-Quaker Co., Ltd.) were added to 100 parts by weight of the spherical artificial ceramic casting sand shown in Example 1. The mixture was stirred and formed into a mold having a sand/metal ratio of 4.

A cast iron melt (FC200) at 1400°C was poured into this mold and then cooled, and the mold was treated with a crusher to give recovered sand. This recovered sand was subjected twice to drying grinding treatment at a sand feed rate of 3.0 t/hr in an USR-type sand-reclaiming machine manufactured by Sintokogio, Ltd., to give reclaimed sand. This reclaimed sand was subjected once more to mold making and casting as described above, followed by cooled, and the mold was treated with a crusher to give recovered sand having an LOI of 0.79%. This recovered sand was subjected to sand reclamation under the same conditions as described above (sand feed rate was 3.0 t/hr, and dry grinding treatment was conducted twice) in the USR-type sand-reclaiming machine, to give reclaimed sand having an LOI of 0.53%, and this reclaimed sand was used as the sand for evaluation.

0.04 part by weight of various kinds of additives was mixed with 100 parts by weight of the reclaimed sand. Then, 80 kg of the resulting sand was introduced into a dry casting sand reclaiming apparatus (Hybrid Sand Master, type HSM1115, manufactured by Nippon Chuzo Co., Ltd.) and subjected to dry grinding treatment by batch treatment at a rotor rotation number of 2600 rpm for treatment times of 6 minutes, 12 minutes and 30 minutes respectively, to give reclaimed sand. When the dry grinding treatment was conducted, dust collection was carried out by floating releasable organic components from a fluidized layer. Analytical values (LOI) of the reclaimed sand in each of the treatment times and the strength of a mold were measured in the same manner as in Example 1. The results are shown in Table 2. The dimethyl silicone oil used in Examples 4 to 9 and Comparative Examples 3 to 6 was KF-96-30CS manufactured by Shin-Etsu Chemical Co. The used ethyl silicate condensate was Ethyl Silicate 40 manufactured by Colcoat Co., Ltd.

The used polyoxyethylene lauryl ether (the average number of added EO moles is 2) was Emulgen 102KG. Oleyl alcohol, 1-octanol, 1,4-butanediol, 1-butanol and oleic acid were reagents manufactured by Wako Pure Chemical Industries, Ltd. Physical properties thereof are shown in Table 2. The boiling points of the additives used in Example 4,7 and Comparative Example 6 are values disclosed in a catalogue published by the manufacturer.

• Ghouchi-Eskandar, Nasrin; Simovic, Spomenka; Prestidge, Clive A 2012-02-28 Submicron oil-in-water (o/w) emulsions stabilised with conventional surfactants and silica nanoparticles were prepared and freeze-dried to obtain free-flowing powders with good redispersibility and a three-dimensional porous matrix structure. Solid-state emulsions were characterised for visual appearance, particle size distribution, zeta potential and reconstitution properties after freeze-drying with various sugars and at a range of sugar to oil ratios.

Comparative degradation kinetics of all-trans-retinol from freeze-dried and liquid emulsions was investigated as a function of storage temperatures. Optimum stability was observed for silica-coated oleylamine emulsions at 4 °C in their wet state. The half-life of all-trans-retinol was 25.66 and 22.08 weeks for silica incorporation from the oil and water phases respectively. This was ∼4 times higher compared to the equivalent solid-state emulsions with drug half-life of 6.18 and 6.06 weeks at 4 °C. Exceptionally, at a storage temperature of 40 °C, the chemical stability of the drug was 3 times higher in the solid-state compared to the wet emulsions which confirmed that freeze-drying is a promising approach to improve the chemical stability of water-labile compounds provided that the storage conditions are optimised.

Oliveira 2013-06-01 Full Text Available Asphaltenes can cause enormous losses in the oil industry, because they are soluble only in aromatic solvents. Therefore, they must be removed from the petroleum before it is refined, using flocculant agents. Aiming to find new materials that can work as flocculant agents to asphaltenes, cobalt ferrite nanoparticles were chemically modified through acid-base reactions using dodecylbenzene sulfonic acid (DBSA to increase their lipophilicity. Nanoparticle synthesis was performed using the co-precipitation method followed by annealing of these nanoparticles, aiming to change the structural phase. Modified and unmodified nanoparticles were tested by FTIR-ATR, XRD and TGA/DTA. In addition, precipitation onset of the asphaltenes was performed using modified and unmodified nanoparticles.

These tests showed that modified nanoparticles have a potential application as flocculant agents used to remove asphaltenes before oil refining, since the presence of nanoparticles promotes the asphaltene precipitation onset with the addition of a small amount of non-solvent. • Oliveira, G.E.; Clarindo, J.E.S.; Santo, K.S.E., E-mail: geiza.oliveira@ufes.br [Universidade Federal do Espirito Santo (CCE/DQUI/UFES), Vitoria, ES (Brazil). Centro de Ciencias Exatas. De Quimica; Souza Junior, F.G. [Universidade Federal do Rio de Janeiro (IMA/UFRJ), Rio de Janeiro, RJ (Brazil). Instituto de Macromoleculas 2013-11-01 Asphaltenes can cause enormous losses in the oil industry, because they are soluble only in aromatic solvents. Therefore, they must be removed from the petroleum before it is refined, using flocculant agents.

Aiming to find new materials that can work as flocculant agents to asphaltenes, cobalt ferrite nanoparticles were chemically modified through acid-base reactions using dodecylbenzene sulfonic acid (DBSA) to increase their lipophilicity. Nanoparticle synthesis was performed using the co-precipitation method followed by annealing of these nanoparticles, aiming to change the structural phase. Modified and unmodified nanoparticles were tested by FTIR-ATR, XRD and TGA/DTA.

In addition, precipitation onset of the asphaltenes was performed using modified and unmodified nanoparticles. These tests showed that modified nanoparticles have a potential application as flocculant agents used to remove asphaltenes before oil refining, since the presence of nanoparticles promotes the asphaltene precipitation onset with the addition of a small amount of non-solvent (author) • Shenava Aashritha 2013-10-01 Full Text Available The aim of this study was to evaluate the antimicrobial activity of silvercolloidal nanoparticles which were synthesised by chemical reduction. Silver nanoparticles were synthesized by reduction of silver nitrate with sodium citrate.

The presence of silver nanoparticles was detected by atomic absorption spectroscopy. Antifungal activity of silver nanoparticles was detected by the zone of inhibition. Silver nanoparticles exhibited a characteristic surface plasmon resonance band that is measured by UV-Vis spectroscopy, showing a typical absorbance peak for nanoparticles centred at 430 nm. The antifungal activity of silver nanoparticles was measured by the zones of inhibition by Kirby Bauer sensitivity testing which were measured after 24 h of incubation at 370C of Candida albicans growth on sabouraud dextrose agar.

This study, integrates nanotechnology leading to possible advances in the formulation of new types of fungicide. • A Oudhia; P Bichpuria 2014-02-01 In the present work, we report green synthesis of tartaric acid (TA) and triethanolamine (TEA) capped cadmium selenide quantum dots (CdSe QDs) employing chemical bath deposition (CBD) method.

The mechanism of capping using non-toxic binary capping agents is also discussed. Stable QDs of various sizes were obtained by varying pH of the bath. The structural, morphological and spectroscopic characterization of the as-prepared samples by XRD, SEM, optical absorption and photoluminescence (PL) is also reported. • CS Albuquerque 2014-03-01 Full Text Available An experiment was carried out to determine the chemical composition, metabolizable energy values, and coefficients of nutrient digestibility of corn germ meal for layers. The chemical composition of corn germ meal was determined, and then a metabolism assay was performed to determine its apparent metabolizable energy (AME and apparent metabolizable energy corrected for nitrogen (AMEn values and its dry matter and gross energy apparent metabolizability coefficients (CAMDM and CAMGE, respectively. In the 8-day assay (four days of adaptation and four days of total excreta collection, 60 29-week-old white Lohman LSL layers were used. A completely randomized experimental design, with three treatments with five replicates of four birds each, was applied.

Treatments consisted of a reference diet and two test diets, containing 20 or 30% corn germ meal. Results were submitted to analysis of variance and means were compared by the Tukey tests at 5% probability level. The chemical composition of corn germ meal was: 96.39% dry matter, 49.48% ether extract, 1.87% ashes, 7243 kcal gross energy/kg, 11.48% protein, 0.19% methionine, 0.21% cystine, 0.48% lysine, 0.40% threonine, 0.72% arginine, 0.35% isoleucine, 0.83% leucine, 0.57% valine, and 0.37% histidine, on as-fed basis. There were no statistical differences in AME, AMEn, CAMDM, and CAMGE values with the inclusion of 20 and 30% corn germ meal in the diets. On dry matter basis, AME, AMEn, CAMDM, and CAMGE values of corn germ meal were: 4,578 and 4,548 kcal/kg, 4,723 and 4,372 kcal/kg, 64.95 and 61.86%, respectively. • Sahebian, S.; Zebarjad, S.

M.; Vahdati Khaki, J.; Lazzeri, A. 2016-07-01 In this paper, nickel oxide (NiO) nanoparticles have been fabricated using wet method and deposited on the surface of multi-walled carbon nanotube (MWCNT). To do so, functional groups were introduced on the surface of MWCNTs by treating with concentrated nitric acid. Nickel oxide nanoparticles were formed on the surface of functionalized MWCNTs by incipient wetness impregnation of nickel nitrate, and the resultant product was calcinated in air atmosphere. Characteristics of the NiO/MWCNT were examined by various techniques, for example, Fourier transform spectroscopy (FTIR), X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), thermogravimetric analyzer (TGA), and nitrogen adsorption-desorption isothermal as well as vibrating sample magnetometer (VSM).

The FTIR spectra showed that carboxyl and hydroxyl functional groups existed on the surface of MWNTs after modification by concentrated nitric acid. The pattern of XRD indicated that MWNTs and nickel oxide nanoparticles coexisted in the NiO/MWCNT sample.

The TEM images revealed that the NiO nanoparticles were distributed on the surface of the MWNTs, with the size ranging from 5 to 60 nm. Thermogravimetric analysis proved that NiO content decorated on MWCNTs was 80 and 15 wt%. The results of the Brunauer-Emmett-Teller (BET) data showed that the slight increment in the specific surface areas and porosities in the presence of the NiO nanoparticles on the surface of CNT. • Subramanian, S. 2013-01-01 The exact manner in which preferential (e.g., much faster than average) flow occurs in the subsurface through small fractures or permeable connected pathways of other kinds is important to many processes but is difficult to determine, because most chemical tracers diffuse quickly enough from small flow channels that they appear to move more uniformly through the rock than they actually do.

We show how preferential flow can be assessed by injecting 2 to 5 nm carbon particles (C-Dots) and an inert KBr chemical tracer at different flow rates into a permeable core channel that is surrounded by a less permeable matrix in laboratory apparatus of three different designs. When the KBr tracer has a long enough transit through the system to diffuse into the matrix, but the C-Dot tracer does not, the C-Dot tracer arrives first and the KBr tracer later, and the separation measures the degree of preferential flow. Tracer sequestration in the matrix can be estimated with a Peclet number, and this is useful for experiment design. A model is used to determine the best fitting core and matrix dispersion parameters and refine estimates of the core and matrix porosities. Almost the same parameter values explain all experiments. The methods demonstrated in the laboratory can be applied to field tests.

If nanoparticles can be designed that do not stick while flowing through the subsurface, the methods presented here could be used to determine the degree of fracture control in natural environments, and this capability would have very wide ranging value and applicability. • Roth, Olivia; Hasselberg, Hanna; Jonsson, Mats 2009-01-01 In a deep repository for spent nuclear fuel, U(VI)(aq) released upon dissolution of the fuel matrix could, in reducing parts of the system, be converted to U(IV) species which might coalesce and form nanometer-sized UO 2 particles. This type of particles is expected to have different properties compared to bulk UO 2(s). Hence, their properties, in particular the capacity for oxidant consumption, must be investigated in order to assess the effects of formation of such particles in a deep repository. In this work, methods for radiation chemical synthesis of nanometer-sized UO 2 particles, by electron- and γ-irradiation of U(VI) solutions, are presented. Electron-irradiation proved to be the most efficient method, showing high conversions of U(VI) and yielding small particles with a narrow size distribution (22-35 nm). Stable colloidal suspensions were obtained at low pH and ionic strength (pH 3, I = 0.03).

Furthermore, the reactivity of the produced UO 2 particles towards H 2O 2 is investigated. The U(IV) fraction in the produced particles was found to be ˜20% of the total uranium content, and the results show that the UO 2 nanoparticles are significantly more reactive than micrometer-sized UO 2 when it comes to H 2O 2 consumption, the major part of the H 2O 2 being catalytically decomposed on the particle surface. • Taarning, Esben; Christensen, Claus H. 2007-01-01 One of the greatest challenges that the chemical industry faces today is to become less dependent on fossil resources, and oil in particular. One way of addressing this challenge is to find ways to transform renewable resources into commodity chemicals.

Renewable resources such as carbohydrates a. That supported gold nanoparticles are highly active catalysts for oxidizing alcohols and aldehydes using oxygen as the oxidant. This perspective will focus on the use of gold nanoparticles in the oxidation of renewables. Kleffmann 2008-11-01 Full Text Available In the present pilot study, an optimized LOPAP instrument (LOng Path Absorption Photometer for the detection of nitrous acid (HONO in the atmosphere (DL 0.2 pptV was tested at the high alpine research station Jungfraujoch at 3580 m altitude in the Swiss Alps under conditions comparable to polar regions. HONO concentrations in the range.