JP2009191328A - Metal recovery plant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new metal recovery plant. <P>SOLUTION: The metal recovery plant is provided with a melting vessel, in which a treating objective material containing tungsten carbide and binder, is treated in the solution containing ferric chloride and hydrochloric acid at the temperature range of 81-100°C, and a first crusher, with which flake containing the tungsten carbide generated with the treatment of the above melting vessel, is crushed. Here, it is desirable that a regenerating vessel for taking in the solution flown out from the melting vessel and for regenerating ferrous chloride contained in the solution into the ferric chloride, is included, and the solution containing the regenerated ferric chloride is returned into the melting vessel. Also, a washing vessel for washing the material having the prescribed particle diameter or smaller in the particle material obtained with the first crusher, and a second crusher for crushing the fine particles obtained with the above washing vessel are preferably included. Furthermore, it is desirable that a condenser for condensing exhaust gas exhausted out from the melting vessel is included and the obtained condensed solution is returned into the melting vessel. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a novel metal recovery plant.

  Tungsten (W), which is a kind of rare metal in which resources are unevenly distributed, is used for various purposes. For example, cutting tools, molds, tools for civil engineering mines, cemented carbide products such as storage cases, special steels such as high-speed steel and alloy tool steel, other electrical / electronic parts, shielding materials, sports equipment, catalysts, pigments There are products such as.

  On the other hand, increasing the recycling rate of tungsten (W) is an important issue. In order to increase the recycling rate of tungsten (W), it is necessary to reduce the recovery cost.

  However, the conventional method for recovering tungsten (W), that is, the alkali leaching method, the alkali melting method, and the electrolysis method has a problem that a long process is required. That is, the conventional method for recovering tungsten (W) required a long process of going through ammonium paratungstate (APT).

  Therefore, attention has been focused on a method for obtaining tungsten carbide (WC) or the like directly from the used cemented carbide, not the conventional method requiring a long process. The following technologies have been developed to achieve this goal.

  First, the tool waste containing tungsten carbide or the like and a metal binder is immersed in an aqueous solution containing either or both of ferric chloride and cupric chloride to elute and separate the metal binder, and then tungsten carbide. Etc. (see Patent Document 1).

  Second, a material containing tungsten carbide or the like and a metal binder, an aqueous solution containing one or a mixture of two or more of ferric chloride, ferric nitrate, and cupric chloride, or In this method, the metal binder is eluted and separated by immersing in an aqueous solution obtained by adding an inorganic acid to the aqueous solution, and then tungsten carbide or the like is separated (see Patent Document 2).

Japanese Patent Publication No.56-5685 Japanese Patent Publication No.56-36692

  However, in Patent Document 1, it is reported that “ferrous chloride and the like may be hydrolyzed at a treatment temperature of 80 ° C. or higher” (from the lower left column on page 2 to the first column on the right column on the first line). is doing.

The reaction formula is as follows (Chemical Dictionary Dictionary, Vol. 1, 1050).
3FeCl ₂ + 4H ₂ O → Fe ₃ O ₄ + 6HCl + H ₂
6FeCl ₂ + 3H ₂ O → 4FeCl ₃ + Fe ₂ O ₃ + 3H ₂

It has been reported that similarly a ferric chloride also be hydrolyzed at about 70 ° C. of hydrated iron oxide _{(III) Fe 2 O 3 ·} H 2 O ( edited by the Chemical Society of Japan Experimental Chemistry Lecture, pp. 9, Volume 339).

If the processing temperature is high, the following problems are considered. (1) Ferric chloride, the active substance in the solution, is wastefully hydrolyzed and becomes inactive iron oxides. (2) If these iron oxides are by-produced, they are insoluble and in the form of fine powder, resulting in poor filterability, and may be mixed into the target product obtained as a filtration residue. (3) The ferrous chloride produced in the following main reaction is also hydrolyzed into insoluble and finely divided iron oxides as in the above reaction formula, and the same problem as in item (2) occurs.
M + 2FeCl ₃ → MCl ₂ + 2FeCl ₂ (M: metal of the binder)

  Further, in Patent Document 2, “If the temperature exceeds 80 ° C., the metal, carbide, etc. remaining as a residual solid may be oxidized, so the upper limit of the temperature of these eluates is 80 ° C.” (right side of page 2) Column lines 28-30)).

  Oxidation of carbides and the like causes the following problems. That is, when carbide or the like becomes an oxide, tungsten (Wt), then tungsten (W), then tungsten carbide (WC), then oxide (tungsten oxides), then tungsten paratungstate (APT) Can't get carbide (WC).

Therefore, development of a metal recovery plant that solves such problems is desired.
The present invention has been made in view of such problems, and an object thereof is to provide a novel metal recovery plant.

  In order to solve the above-mentioned problems and achieve the object of the present invention, the metal recovery plant of the present invention comprises a treatment object containing tungsten carbide and a binder in a solution containing ferric chloride and hydrochloric acid at 81 to 100 ° C. And a first pulverizer for pulverizing the tungsten carbide-containing flakes produced by the treatment in the dissolution vessel.

  Here, although not necessarily limited, the binder preferably includes any one selected from cobalt, nickel, chromium, and iron, or a combination of any two or more. Moreover, although not necessarily limited, it is more preferable that the temperature range is 85-98 degreeC, and it is still more preferable that it is 90-98 degreeC. Although not limited, the concentration of ferric chloride is preferably in the range of 0.5 to 3.0 mol / l, and more preferably in the range of 1.0 to 2.0 mol / l. Moreover, although not necessarily limited, it is preferable that the density | concentration of hydrochloric acid exists in the range of 0.3-8.0 mol / l, and it is still more preferable that it exists in the range of 0.5-5.0 mol / l. Although not limited, the concentration ratio of hydrochloric acid to ferric chloride (hydrochloric acid / ferric chloride) is preferably in the range of 0.5 to 5.0, and in the range of 1.0 to 2.0. Is more preferable. Although not limited, the binder includes any one selected from cobalt, nickel, chromium, and iron, or a combination of any two or more, and the temperature is in the range of 90 to 98 ° C. The concentration of ferric chloride is in the range of 1.0 to 2.0 mol / l, the concentration of hydrochloric acid is in the range of 0.5 to 5.0 mol / l, and the concentration ratio of hydrochloric acid to ferric chloride (hydrochloric acid / chloride Ferric) is preferably in the range of 1.0 to 2.0. Although not limited, it has a regeneration tank that takes in the solution flowing out from the dissolution tank and regenerates ferrous chloride contained in the solution into ferric chloride, and the regenerated chloride It is preferable to reflux the dissolving solution containing ferric iron to the dissolving tank. Further, although not limited, among the powder obtained by the first pulverizer, a washing tank for washing particles having a predetermined particle size or less, and a second pulverizing fine particles obtained in the washing tank It is preferable to have a pulverizer. Moreover, although not necessarily limited, it is preferable to have a condenser that condenses the exhaust gas discharged from the dissolution tank, and to return the obtained condensate to the dissolution tank. Although not limited, it has a regeneration tank that takes in the solution flowing out from the dissolution tank and regenerates ferrous chloride contained in the solution into ferric chloride, and the regenerated chloride A solution containing ferric iron is refluxed to the dissolution tank, and a powder obtained in the first pulverizer is used to wash a powder having a predetermined particle size or less, and fine particles obtained in the washing tank. It is preferable to have a second pulverizer for pulverizing the gas, to condense the exhaust gas discharged from the dissolution tank, to have a condenser, and to return the obtained condensate to the dissolution tank.

  The present invention has the following effects.

  The metal recovery plant of the present invention includes a dissolution tank for treating a treatment object containing tungsten carbide and a binder in a temperature range of 81 to 100 ° C. in a solution containing ferric chloride and hydrochloric acid, and treatment of the dissolution tank Since it has the 1st grinder which grind | pulverizes the tungsten carbide containing flakes produced | generated by this, a novel metal recovery plant can be provided.

Hereinafter, the best mode for carrying out the invention relating to a metal recovery plant will be described.
FIG. 1 is a diagram showing the best mode for carrying out the invention according to a metal recovery plant.

The WC collection process will be described.

  The dissolution tank P1 treats an object to be treated containing tungsten carbide and a binder in a predetermined temperature range in a solution containing ferric chloride and hydrochloric acid.

  The dissolution tank P1 is made of, for example, a steel-lined tank made of rubber and has a lid. The dissolution tank P1 is not limited to rubber lining, and other corrosion-resistant materials can be used, and can be selected from the viewpoint of economy and durability. The material of the apparatus and apparatus in the following description can also be selected from the viewpoint of economy and durability.

  The types of objects to be treated include scraps made of cemented carbide, such as cutting tools (chips, drills, end mills, etc.), dies (molding rolls, molding dies, etc.), civil engineering mining tools (oil drilling tools, rocks) A crushing tool or the like), a storage case (such as a spectacle case) or the like can be employed.

  Examples of the main component in the object to be treated include tungsten carbide (WC).

Examples of the additive component in the object to be treated include TiC, TaC, NbC, VC, Cr ₃ C _{2 and the} like. It is added as an additive for the purpose of improving heat resistance and suppressing WC grain growth during sintering. The example of the ratio to add is 0.1 to 10% (total component).

  As the binder, a material including any one selected from cobalt, nickel, chromium, iron, etc., or any combination of two or more can be employed. The example of a ratio to mix | blend is 6 to 30%.

  The treatment temperature is preferably in the range of 81-100 ° C. The treatment temperature is more preferably in the range of 85 to 98 ° C. More preferably, the treatment temperature is in the range of 90-98 ° C.

  When the treatment temperature is 81 ° C. or higher, there is an advantage that the reaction rate can be kept large. When the treatment temperature is 85 ° C. or higher, this effect becomes more remarkable. If the treatment temperature is 90 ° C. or higher, this effect becomes even more remarkable.

  When the treatment temperature is 100 ° C. or lower, there are advantages that the amount of exhaust gas generated can be suppressed and bumping can be prevented. When the treatment temperature is 98 ° C. or lower, this effect becomes more remarkable.

The FeCl ₃ concentration is preferably in the range of 0.5 to 3.0 mol / l. Further, the FeCl ₃ concentration is more preferably in the range of 1.0 to 2.0 mol / l.

When the FeCl ₃ concentration is 0.5 mol / l or more, there is an advantage that the reaction rate can be largely maintained. This effect becomes more remarkable when the FeCl ₃ concentration is 1.0 mol / l or more.

When the FeCl ₃ concentration is 3.0 mol / l or less, there is an advantage that the reaction rate can be largely maintained. This effect becomes more remarkable when the FeCl ₃ concentration is 2.0 mol / l or less.

  The HCl concentration is preferably in the range of 0.3 to 8.0 mol / l. The HCl concentration is more preferably in the range of 0.5 to 5.0 mol / l.

  When the HCl concentration is 0.3 mol / l or more, there are advantages that the reaction rate can be kept large and the filterability of the slurry can be improved. This effect becomes more remarkable when the HCl concentration is 0.5 mol / l or more.

  When the HCl concentration is 8.0 mol / l or less, there are advantages that the reaction rate can be kept large and the filterability of the slurry can be improved. This effect becomes more prominent when the HCl concentration is 5.0 mol / l or less.

The concentration ratio (HCl / FeCl ₃ ) is preferably in the range of 0.5 to 5.0. The concentration ratio (HCl / FeCl ₃ ) is more preferably in the range of 1.0 to 2.0.

When the concentration ratio (HCl / FeCl ₃ ) is 0.5 or more, there are advantages that the reaction rate can be maintained large and the filterability of the slurry can be improved. This effect becomes more remarkable when the concentration ratio (HCl / FeCl ₃ ) is 1.0 or more.

When the concentration ratio (HCl / FeCl ₃ ) is 5.0 or less, there are advantages that the reaction rate can be kept large and the filterability of the slurry can be improved. This effect becomes more remarkable when the concentration ratio (HCl / FeCl ₃ ) is 2.0 or less.

  In the dissolution tank P1, a slurry S6 is obtained by processing a processing object including tungsten carbide and a binder. Slurry S6 is a mixture of a solution in which a binder or the like is dissolved and a flake made of cemented carbide scrap as a main component.

  The purpose of the filter P2 is to treat the slurry S6 and separate it into flakes and filtrate. As the filter P2, for example, an open filter such as Nutsche can be used. If it is an open type filter, there are obtained effects that there is no damage to the constituent materials and that undissolved materials can be sorted by hand.

NH ₃ solution S8 is added to the filter after filtration to remove a small amount of WO ₃ adhering to the flakes. As the NH ₃ solution S8, for example, one having an NH ₃ concentration of about 1 mol / l can be used. The NH ₃ solution S8 is preferably one having an NH ₃ concentration of 1 to ₃ mol / l. As the NH ₃ solution S8, commercially available aqueous ammonia (25%) can be diluted and used.

  The flakes (WC) S9 can be obtained by filtering the slurry S6 with the filter P2. The flakes (WC) S9 are flakes made of the main component of cemented carbide scrap.

  Undissolved material S10 is thicker than flakes (WC) S9, and is a lump of cemented carbide scrap having a large size. That is, it did not dissolve. By visually observing the open filter, the undissolved material S10 can be taken out. The undissolved material S10 is again put into the dissolution tank P1 and dissolved to make a thin piece.

  In the dryer P3, the flakes are dried and the adhering water is removed in order to crush (dry) the next step. As the dryer P3, an incubator, a muffle furnace, an airflow dryer, a vacuum dryer, or the like can be employed.

The (dry type) pulverizer P4 (first pulverizer) is used to coarsely pulverize flakes. As the (dry) pulverizer P4, a ball mill, a rod mill, a collision pulverizer, or the like can be used. As a constituent material of the (dry) pulverizer P4, stainless steel (hereinafter abbreviated as “stainless”), ceramics, nylon, cemented carbide, or the like can be used.
If the pulverization by the (dry type) pulverizer P4 is stopped by coarse pulverization, there is an effect that the constituent materials are not damaged, and the mixed undissolved substances can be removed by sieving.

  The undissolved material having a size of about 1 mm or more is separated on the sieve by the sieving device P5. As the sieving device P5, a vibrating sieve or the like can be employed. When the undissolved material is removed by the sieving device P5, it is easy to remove the binding material remaining in a trace amount by washing in the next step.

  Under (WC powder) S11 is particles of flakes having a size smaller than 1 mm (about 10 μm to 1 mm). Under (WC powder) S11 is recovered as fine granules (WC). Since the binder component in the under (WC powder) S11 is less than the allowable value, it can be used as a raw material for ferrotungsten (Fe-W).

  The over (coarse) S12 is an undissolved material, that is, a flake in which the binder remains, and has a size of about several mm. The over (coarse) S12 is again put into the dissolution tank and melted and thinned.

  In the washing tank P6, the under (WC powder) S11 is washed with the solution S2, and a small amount of the remaining binder and some additives are washed away to an ultra-low concentration.

  The washing temperature is preferably in the range of 81-100 ° C. When the washing temperature is 81 ° C. or higher, there is an advantage that the reaction rate can be kept large. When the washing temperature is 100 ° C. or lower, there are advantages that the amount of exhaust gas generated can be suppressed and bumping can be prevented.

  The cleaning tank P6 is made of, for example, a steel-lined steel-lined tank and has a lid. The cleaning tank P6 is not limited to rubber lining, and other corrosion-resistant materials can be used, and can be selected from the viewpoint of economy and durability.

  In the washing tank P6, hydrochloric acid can be used instead of the solution S2. The concentration of hydrochloric acid is preferably in the range of 0.5 to 5 mol / l. Washing the under (WC powder) S11 with hydrochloric acid in this concentration range has the effect of reducing the Fe concentration remaining in the fine particles.

  The slurry S13 is a mixture of a solution obtained by dissolving a binder or the like and coarsely pulverized flakes. When hydrochloric acid is used instead of the solution S2, the slurry S13 is a mixture of hydrochloric acid in which the binder or the like is dissolved and coarsely crushed flakes.

In the filter P7, the slurry S13 is processed and separated into roughly crushed flakes and a filtrate. As the filter P7, for example, a hermetic filter such as a filter press can be employed. When the hermetic filter is used, there are effects that the constituent materials are not damaged, a high cleaning effect is obtained, and a high dehydrating effect is obtained.
After filtration, it is washed with NH ₃ solution S8 and a small amount of WO ₃ produced is eluted from the solid as ammonium paratungstate (APT).

  The fine particles (WC) S14 are thin fine particles obtained by washing and filtering the under (WC powder) S11.

  In the dryer P8, the fine flakes are dried to remove the adhering water in order to pulverize in the next step (dry). As the dryer P8, an incubator, a muffle furnace, an airflow dryer, a vacuum dryer, or the like can be used.

  In the (dry type) pulverizer P9 (second pulverizer), the fine flakes after washing and drying are finely pulverized. Since the binder is washed and removed to an ultra-low concentration, even if it is pulverized, it does not damage the constituent materials of the pulverizer, that is, the impurity level does not increase, and the original particle size (particles when the cemented carbide was produced) There is an effect that fine pulverization up to a diameter) is possible.

  As the (dry) pulverizer P9, a ball mill, a rod mill, a collision pulverizer, or the like can be employed. As a constituent material of the (dry) pulverizer P9, nylon, cemented carbide, ceramics, or the like can be employed.

  In the classifying device P10, fine particles after fine pulverization are classified into under (WC) S15 and over (coarse) S16. As the classification device P10, for example, an airflow type or liquid flow type classification device such as a cyclone classifier can be adopted.

  Over (coarse grain) S16 is a fine grain after fine pulverization larger than 15 μm. The over (coarse) S16 is supplied to the (dry) pulverizer P9 and pulverized again. Since the over (coarse) S16 does not contain a binder component, it can be pulverized to the original particle size.

  Under (WC) S15 is a general term for three types of products (WC fine particles), sub-micron, micron, and micron-over. Here, submicron means a particle diameter in the range of 0.1 to 1.0 μm, micron means 1.0 to 5.0 μm, and micron over means 5.0 to 15 μm. The true specific gravity of under (WC) S15 is as large as 15.5 g / ml.

  The effect obtained by a series of operations in the above-described WC recovery process will be described. The purpose of the WC recovery process is to recover the cemented carbide scrap into WC particles of the original particle size. The purpose of the WC recovery process can be achieved with the shortest process.

  The dissolved solution adjustment step will be described.

The solution S17 is a solution after being used for elution of the cemented carbide scrap binder in the dissolution tank P1. In the solution S17, part of FeCl ₃ is FeCl ₂ compared to the solution before the binder elution. Further, increased content of NiCl _2, CoCl _2, a portion of the additional material of cemented carbide scrap are eluted as chloride.

  The filtrate S26 has the same properties as the solution S17 described above.

The solution S29 has the same properties as the solution S17 described above. However, the consumed amount of FeCl _{3 and} the content of binder and additive are less than that of the solution S17.

  The filtrate S30 has the same properties as the above-described solution S29.

  In the filter P12, the above-mentioned solution S17, filtrate S26, solution S29, and filtrate S30 are filtered and separated into sludge S18 and filtrate S19. The flakes suspended in the solution S17, the filtrate S26, the solution S29, and the filtrate S30 are removed as sludge S19.

  As the filter P12, for example, an open type filter such as Nutsche or a closed type filter such as a filter press can be employed. By using an open filter or a closed filter, flakes can be efficiently removed.

  The sludge S18 is a flake suspended in the solution S17, the filtrate S26, the solution S29, and the filtrate S30. The sludge S18 is supplied to the WC recovery process through the dryer P3.

  The filtrate S19 is a solution S17, a filtrate S26, a solution S29, and a filtrate S30 from which the suspended flakes have been removed.

In the regeneration tank P13, industrial water and chlorine are added to the filtrate S19 to regenerate ferrous chloride contained in the solution into ferric chloride. Ferrous chloride and chlorine react as follows to produce ferric chloride.
2FeCl ₂ + Cl ₂ → 2FeCl ₃

  The regeneration tank P13 is composed of, for example, a steel-lined rubber-lined tank and has a lid. The regeneration tank P13 is not limited to rubber lining, and other corrosion-resistant materials can be used, and can be selected from the viewpoints of economy and durability.

As Cl ₂ (S20), for example, chlorine gas having a purity of 99.9% or more can be used.

  The industrial water S7 is used for adjusting the component concentration of the solution. The industrial water S7 is not required to be as chlorinated as drinking water, but it is necessary not to include a component that lowers the purity of the final product (WC).

The adjustment tank P14 is used to adjust the concentration of FeCl ₃ and HCl in the solution. The adjustment is performed by adding the shortage of FeCl ₃ and HCl to the adjustment tank P14 so that the concentration of FeCl ₃ and HCl in the dissolution tank P1 is maintained within a preferable range.

  The adjusting tank P14 is made of, for example, a steel-lined tank made of rubber and has a lid. The adjustment tank P14 is not limited to rubber lining, and other corrosion-resistant materials can be used, and can be selected from the viewpoint of economy and durability.

As the FeCl ₃ solution S21, for example, a 38% aqueous solution of FeCl ₃ can be used.

  As the HCl solution S22, a 35% HCl aqueous solution can be used.

  The warmer P15 is used to heat the solution exiting the adjustment tank P14 to a predetermined temperature. As the predetermined temperature, a temperature 3 to 10 ° C. higher than the treatment temperature of the dissolution tank P1 and the cleaning temperature of the cleaning tank P6 can be employed.

  The warmer P15 includes a pipe and a tank. Heat exchange is performed by passing a solution and a heat medium (for example, water vapor, heat medium oil, etc.) through either a pipe or a tank.

  The heated solution S2 is refluxed to the dissolution tank P1 and the cleaning tank P6.

  The effect obtained by a series of operations in the above-described dissolution liquid adjustment step will be described. By the solution adjusting step, the solution used for processing the processing object including tungsten carbide and the binder can be regenerated and repeatedly used. In addition, this process can reduce the environmental load and the operating cost. Further, the sludge S18 separated by this process can be supplied to the WC recovery process through the dryer P3. Further, according to this step, in order to prevent the concentration of the binder component, a predetermined amount can be extracted to the Ni, Co recovery device P16 (described later). Here, the predetermined amount can be determined according to the content of the binder.

  The condensation process will be described.

The exhaust gas S4 is exhaust gas that evaporates and volatilizes from the dissolution tank P1. The main component is H ₂ O, accompanied by a small amount of HCl and iron chloride mist.

The solution component (H ₂ O, HCl, iron chlorides) contained in the exhaust gas S4 is condensed and recovered by the condenser P11. As the condenser P11, for example, a condenser that circulates cooling water, such as a shell and tube condenser, can be adopted. As a material of the condenser P11, for example, rubber lining, hydrochloric acid resistant stainless steel, or the like can be employed.

The condensate S5 is a component (H ₂ O, HCl, iron chlorides) contained in the exhaust gas S4 condensed by the condenser P11.

The exhaust gas S32 is exhaust gas that evaporates and volatilizes from the cleaning tank P6. The main component is H ₂ O, accompanied by a small amount of HCl and iron chloride mist.

The solution component (H ₂ O, HCl, iron chlorides) contained in the exhaust gas S4 is condensed and recovered by the condenser P18. As the condenser P18, a condenser of a type that circulates cooling water, such as a shell and tube condenser, can be employed. As a material of the condenser P18, for example, rubber lining, hydrochloric acid resistant stainless steel, or the like can be employed.

The condensate S33 is a component (H ₂ O, HCl, iron chlorides) contained in the exhaust gas S32 condensed by the condenser P18.

The effect obtained by a series of operations of the condensation process described above will be described. By adopting a condensation process and condensing / refluxing, the concentration of FeCl ₃ , FeCl ₂ , HCl, etc. can be maintained within the appropriate range in the dissolution tank P1 or the washing tank P6. Sexual deterioration can be prevented.

  The Ni and Co recovery process will be described.

  The Ni, Co recovery device P16 recovers salts of Ni, Co, and other metals (V, Cr, etc.), which are valuable metals, using the filtrate S19 as a starting material. As the Ni, Co recovery device P16, an ion exchange method, a solvent extraction method, a special adsorbent adsorption method, or the like can be employed. Ni, Co and other metals (V, Cr, etc.) are separated from filtrate S19 by Ni, Co recovery device P16, and the separated Ni, Co and other metals are recovered as sulfates, nitrates, hydrochlorides, and the like.

  The Ni salt S23 is a crystal of nickel sulfate, nickel nitrate, or nickel chloride. The level of impurities other than the nickel salt is preferably 2% or less.

  The Co salt S24 is a crystal of cobalt sulfate, cobalt nitrate, or cobalt chloride. The level of impurities other than the cobalt salt is preferably 2% or less.

  Other (salt) S25 is a crystal of sulfate, nitrate, or hydrochloride of a mixture of V, Cr, and the like. V, Cr, etc. will be recovered from this.

  The effect obtained by the series of operations in the Ni and Co recovery process described above will be described. Through the Ni and Co recovery process, valuable metals (Ni, Co) and other metals (V, Cr, etc.) can be recovered without being disposed of.

It will be described WO ₃ recovery process.

The alkali drainage S27 is a liquid obtained by washing and removing a small amount of tungstic acid (WO ₃ ) adhering to the flakes as ammonium tungstate with ammonia water using the filter P2.

The alkaline drainage S31 is a liquid obtained by washing and removing a small amount of tungstic acid (WO ₃ ) adhering to the flakes as ammonium tungstate with ammonia water by the filter P7.

WO ₃ recovery device P17 recovers ammonium paratungstate from ammonium tungstate contained in the alkaline drainage.

  APT (S28) is ammonium paratungstate and is a raw material for metallic tungsten (W) and pigment. The level of impurities other than APT is preferably 1% or less.

Illustrating the effect obtained by the series of operations described above WO ₃ recovery step. APT is obtained from ammonium tungstate contained in the alkaline drainage by the WO ₃ recovery step. If the amount of WO ₃ produced is extremely small and the recovery cost is greater than the APT sales profit, this step can be omitted.

  From the above, according to the best mode for carrying out the present invention, an object to be treated containing tungsten carbide and a binder is in a temperature range of 81 to 100 ° C. in a solution containing ferric chloride and hydrochloric acid. A novel metal recovery plant having a dissolution tank to be processed and a first pulverizer for pulverizing the tungsten carbide-containing flakes produced by the processing of the dissolution tank can be provided.

  The present invention is not limited to the best mode for carrying out the above-described invention, and various other configurations can be adopted without departing from the gist of the present invention.

  Next, specific examples of the present invention will be described. However, it goes without saying that the present invention is not limited to these examples.

Example 1
Two-necked 500ml WC-8% Co-4% Ni cemented carbide molding roll scrap (hereinafter abbreviated as "feeding roll") cut into cubes of about 3x3x2cm with a fluororesin inner cylinder A glass separable flask was charged, and 300 ml of a solution, which was a mixed aqueous solution of 1.0 mol / l-FeCl ₃ and 1.0 mol / l-HCl, was added. A thermometer and a condenser were attached and heated to 95 ° C. in a silicone oil bath for 40 hours.

  After cooling to room temperature, the bulky roll residue (hereinafter abbreviated as “bulk”) was taken out, washed with water and dried, and the weight was measured to be 224.4 g. ) Was 84.7%. The solution part was filtered under reduced pressure with a 17G3 type glass filter, and the residue was washed with water and dried to obtain 31.8 g of gray flakes (hereinafter abbreviated as “thin flakes”). The recovery rate of the flakes from the charging roll was 12.0%.

  The flakes were processed by the mixed acid D dissolution method described in JIS H 1402 (2001) and analyzed by ICP-MS. As a result, the composition was 0.5% Co + 0.3% Ni and the rest was WC. As a result of ICP-MS analysis of the filtrate in the same manner, the contents of Co, Ni, and W were 5.9 g, 2.8 g, and 0.3 g in total 9.0 g.

  The collected lump was heated again to 95 ° C. for 40 hours in a newly prepared solution of the same composition and amount. The weight of the recollected lump was 147.8 g, and the recovery rate from the feed roll was 55.8%. The weight of the recovered flakes was 70.2 g, the recovery rate was 26.5%, the composition was 0.5% Co + 0.4% Ni, and the rest was WC. The contents of Co, Ni, and W in the filtrate were 4.2 g, 2.1 g, 0.2 g, and 6.5 g in total.

  The recovered lump was treated a third time by the same method to obtain a lump of 61.9 g (recovery rate 23.4%). The weight of the recovered flakes was 78.4 g (recovery rate 29.6%), the composition was 0.4% Co + 0.3% Ni, and the rest was WC. The contents of Co, Ni, and W in the filtrate were 4.9 g, 2.5 g, and 0.2 g, for a total of 7.6 g.

  When the results of the three treatments were totaled, by heating 265.0 g of the feed roll at 95 ° C. for 120 hours, 68.1% (180.4 g) of the feed roll could be recovered as a flake with a purity of 99% or more. The total content of Co, Ni, and W in the filtrate was 15.0 g, 7.4 g, and 0.7 g, totaling 23.1 g, which was 8.7% of the charged rolls. The results of Example 1 are shown in Table 1.

Note that yellow tungsten oxides were hardly attached to the recovered flakes in each treatment, and from the ICP-MS analysis results of the filtrate, the amount of tungsten oxides secondary to tungsten oxide was 0.7g (WO ₃ conversion 0.9g). There was very little raw. When nitric acid, which is an oxidizing inorganic acid, is used as in Example 5 of Patent Document 2, oxidation of W or WC may occur at a high temperature, but it is considered that oxidation of WC hardly occurs in a hydrochloric acid system.

The filterability of the solution part was good at any treatment, and filtration was completed in about 2 minutes. The reason for the good filterability was the addition of HCl, which prevented hydrolysis of FeCl ₃ and FeCl ₂ even at a high temperature of 95 ° C. This is probably because there was almost no life.

Examples 2-4
The treatment was performed under the same conditions as in Example 1 except that the HCl concentration in Example 1 was changed to 0.5, 2.0 and 5.0 mol / l, respectively. The results of Examples 2 to 4 are shown in Table 1.
In each Example, the by-product of tungsten oxides was very small as in Example 1.
Regarding the filterability of the solution part, each treatment time of each example was good, and the filtration was completed in about 2 minutes.

From the results of Examples 1 to 4, it was confirmed that good results were obtained when the HCl concentration was in the range of 0.5 to 5.0 mol / l. Further, from the results of Examples 1 to 4, it was confirmed that good results were obtained when the concentration ratio of HCl and FeCl ₃ (HCl / FeCl ₃ ) was in the range of 0.5 to 5.0.

Example 5
The treatment was performed under the same conditions as in Example 1 except that the composition of the feed roll in Example 1 was changed to WC-8% Co-4% Ni-1% Cr and the FeCl ₃ and HCl concentrations were each 2.0 mol / l. did. The processing results are shown in Table 2.
Incidentally, the by-product of tungsten oxides was very small as in Example 1.
The filterability of the solution part was good in each treatment, and the filtration was completed in about 2 minutes.

From the results of Examples 1 to 5, it was confirmed that good results were obtained when the FeCl ₃ concentration was in the range of 1.0 to 2.0 mol / l.

Example 6
The treatment was performed under the same conditions as in Example 1 except that the heating time for each treatment in Example 1 was shortened to 8 hours and the number of treatments was 5. The results of the treatment are shown in Table 3. When the results of the fifth treatment (total heating time 40 hours) were compared with the results of the first treatment in Example 1, the flake recovery rate increased significantly. This result shows that since the FeCl ₃ concentration of the solution gradually decreases during the treatment, the treatment effect increases as the exchange time for the newly prepared solution is shorter.
Incidentally, the by-product of tungsten oxides was very small as in Example 1.
The filterability of the solution part was good in each treatment, and the filtration was completed in about 2 minutes.

Example 7
The processing was performed under the same conditions as in Example 1 except that the charging roll in Example 1 was changed to a cemented carbide cutting tool scrap of about 1 × 5 × 5 cm (hereinafter abbreviated as “charging chip”). Note the composition of the charged chip TiC, TaC, NbC, VC and Cr ₃ C ₂ WC-8% was added as an additive to Co-4% Ni-0.6% TiC-0.3% TaC-0.3% NbC-0.3% VC It was -1.0% Cr ₃ C _2. The treatment results are shown in Table 4, except that the additive was hardly dissolved in the same manner as WC except that the amount of VC dissolved was slightly larger.
Incidentally, the by-product of tungsten oxides was very small as in Example 1.
The filterability of the solution part was good in each treatment, and the filtration was completed in about 2 minutes.

Comparative Example 1
The treatment was performed under the same conditions as in Example 1 except that the treatment temperature in Example 1 was changed to 60 ° C. The processing results are shown in Table 5. When the processing temperature is lowered, the flake recovery rate is greatly reduced.
In addition, although the by-product of tungsten oxides was very small, it was slightly more than Example 1 processed at 95 degreeC.
The filterability of the solution part was good in each treatment, and the filtration was completed in about 2 minutes.

Comparative Examples 2-3
The treatment was performed under the same conditions as in Example 1 except that the FeCl ₃ and HCl concentrations in Example 1 were changed to FeCl ₃ /HCl=0.1/1.0 mol / l and 0.4 / 0.4 mol / l, respectively. The treatment results are shown in Table 6. When the FeCl ₃ concentration is lowered, the flake recovery rate is greatly reduced.
In each comparative example, the by-product of tungsten oxides was very small as in Example 1.
Regarding the filterability of the solution part, each treatment time of each comparative example was good, and the filtration was completed in about 2 minutes.

Comparative Example 4
The treatment was carried out under the same conditions as in Example 1 except that HCl in Example 1 was not used and the FeCl ₃ concentration and treatment temperature were changed as shown in Table 7. The treatment results are shown in Table 7. When the treatment temperature is lowered without using HCl, the flake recovery rate is greatly reduced. A further problem is that the filterability of the solution portion was poor. By-product fine-grained reddish brown iron oxides adversely affected the filterability, and filtration time of 1 hour or more was required at any treatment time. Further, since the iron oxides are also mixed in the collected flakes, it has been necessary to remove them by repeated washing with water and decantation.
Incidentally, by-products of tungsten oxides were very slight, but slightly more than in Example 1. When the results of Comparative Examples 1 and 4 were compared with the by-product tungsten oxide amount of Examples 1 to 7, it was confirmed that the by-product amount of tungsten oxides did not increase even when the temperature was raised to 95 ° C.

Example 8
WC-8% Co-4% Ni cemented carbide scrap (molding roll) obtained by dissolving in a mixed aqueous solution of 1.0 mol / l-FeCl ₃ and 1.0 mol / l-HCl at 95 ° C for 120 hours A coarse pulverization test was performed on the obtained flakes.

  In a 250 ml stainless steel pot of P-6 type pulverizer (planetary ball mill), 300.0 g of flakes and 15 stainless steel balls 20 mmφ were put and crushed at 400 rpm for 10 minutes. After pulverization, the crushed pieces were classified with a 1 mm mesh metal mesh, and 2.5 g of over (coarse grains) and 297.5 g of under (WC powder) were obtained.

  The pot and ball were not damaged, and the recovery rate of under was 99.2%. As a result of ICP-MS analysis after treating the under with the mixed acid D dissolution method described in JISH1402 (2001), the concentration of the binder contained in the under is Co = 120ppm, Ni = 270ppm, wear of stainless steel pots and balls Contamination due to was not seen. On the other hand, the recovery rate of over was 0.8%, and the concentration of the binder contained in over measured by the same method was equivalent to that of the starting material.

Example 9
The coarsely pulverized under 100.0 g was charged into a 1,000 ml round flask, and 140 ml of a 3.0 mol / l-HCl aqueous solution having a composition was added. A thermometer, condenser and electromagnetic stirrer were attached and heated to 95 ° C. in a silicone oil bath for 7 hours.

  After cooling to room temperature, the contents of the flask were filtered under reduced pressure with a 17G4 type glass filter, and the filtration residue was washed with water and dried to obtain 99.7 g of a black powder. The recovery rate from under after coarse pulverization was 99.7%.

  Fine particles were treated by the mixed acid D dissolution method described in JISH1402 (2001), and as a result of ICP-MS analysis, the concentration of the binder contained in the washed product was Co = 15 ppm and Ni = 30 ppm.

Example 10
In a 250 ml pot made of cemented carbide of P-6 type pulverizer (planet type ball mill), 1,200 dried fine granules 299.1 g and 1,5 mm of cemented carbide balls 5 mmφ were put and finely pulverized at 400 rpm for 15 minutes. The pot and the ball were not damaged, and the under weight after pulverization was 299.0 g.

  When the particle size distribution of the under-ground after pulverization is measured with a laser diffraction type particle size distribution analyzer, 0.3-1.0 μm = 7%, 1.0-5.0 μm = 45%, 5.0-35 μm = 48%, average particle size = 5.3 μm The result was obtained.

  In addition, the pulverized under was processed by the mixed acid D dissolution method described in JISH1402 (2001), and as a result of ICP-MS analysis, the concentration of the binder contained in the under was Co = 15ppm, Ni = 30ppm, There was no contamination due to wear of the hard alloy pot and balls.

It is a figure which shows the best form for implementing invention concerning a metal recovery plant.

Claims (15)

A dissolution vessel for treating a treatment object containing tungsten carbide and a binder in a solution containing ferric chloride and hydrochloric acid in a temperature range of 81 to 100 ° C .;
A metal recovery plant having a first pulverizer for pulverizing tungsten carbide-containing flakes produced by the treatment of the dissolution tank. 2. The metal recovery plant according to claim 1, wherein the binder includes any one selected from cobalt, nickel, chromium, and iron, or a combination of any two or more. 2. The metal recovery plant according to claim 1, wherein the temperature range is “85 to 98 ° C.” instead of “81 to 100 ° C.”. 2. The metal recovery plant according to claim 1, wherein the temperature range is “90 to 98 ° C.” instead of “81 to 100 ° C.”. The metal recovery plant according to claim 1, wherein the concentration of ferric chloride is in the range of 0.5 to 3.0 mol / l. 2. The metal recovery plant according to claim 1, wherein the concentration of ferric chloride is in the range of 1.0 to 2.0 mol / l. 2. The metal recovery plant according to claim 1, wherein the concentration of hydrochloric acid is within a range of 0.3 to 8.0 mol / l. 2. The metal recovery plant according to claim 1, wherein the concentration of hydrochloric acid is in the range of 0.5 to 5.0 mol / l. 2. The metal recovery plant according to claim 1, wherein the concentration ratio of hydrochloric acid to ferric chloride (hydrochloric acid / ferric chloride) is in the range of 0.5 to 5.0. 2. The metal recovery plant according to claim 1, wherein the concentration ratio of hydrochloric acid to ferric chloride (hydrochloric acid / ferric chloride) is in the range of 1.0 to 2.0. The binder includes any one selected from cobalt, nickel, chromium, and iron, or any combination of two or more.
The temperature is in the range of 90-98 ° C;
The concentration of ferric chloride is in the range of 1.0-2.0 mol / l,
The concentration of hydrochloric acid is in the range of 0.5-5.0 mol / l,
2. The metal recovery plant according to claim 1, wherein the concentration ratio of hydrochloric acid to ferric chloride (hydrochloric acid / ferric chloride) is in the range of 1.0 to 2.0. Taking a solution flowing out from the dissolution tank, and having a regeneration tank for regenerating ferrous chloride contained in the solution into ferric chloride,
2. The metal recovery plant according to claim 1, wherein the regenerated solution containing ferric chloride is refluxed to the dissolution tank. Among the powders obtained by the first pulverizer, a washing tank for washing those having a predetermined particle size or less,
2. The metal recovery plant according to claim 1, further comprising a second pulverizer for pulverizing the fine particles obtained in the washing tank. It has a condenser that condenses the exhaust gas discharged from the dissolution tank,
2. The metal recovery plant according to claim 1, wherein the obtained condensate is refluxed to the dissolution tank. Taking a solution flowing out from the dissolution tank, and having a regeneration tank for regenerating ferrous chloride contained in the solution into ferric chloride,
The regenerated solution containing ferric chloride is refluxed to the dissolution vessel;
Of the powder obtained by the first pulverizer, having a washing tank for washing those having a predetermined particle size or less, and a second pulverizer for pulverizing fine particles obtained in the washing tank,
It has a condenser that condenses the exhaust gas discharged from the dissolution tank,
2. The metal recovery plant according to claim 1, wherein the obtained condensate is refluxed to the dissolution tank.

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