Method for preparing copper chromite black pigment by recycling organic silicon waste contact in organic silicon production

Abstract

The invention discloses a method for preparing a copper chromite black pigment by recycling organic silicon waste contact bodies in organic silicon production. The method specifically comprises the following steps: adding water into the organic silicon waste contact bodies to be treated in the organic silicon production, stirring and leaching, and then carrying out filter pressing to obtain filtrate a and filter residues b; grinding the filter residue b, adding concentrated sulfuric acid, and carrying out acid leaching to obtain an acid-leached material c; the acid leaching material c is merged into the filtrate a for water leaching, then filter pressing is conducted, filtrate d and filter residues e are obtained, the filter residues e are silicon powder, and the silicon powder enters an organic silicon production system; adding a P204 extracting agent into the filtrate d, and extracting to obtain a P204 extracting solution f and an extracted solution g; sulfuric acid is added into the P204 extraction liquid for reverse extraction, and reverse extraction liquid h and raffinate i are obtained; after the strip liquor h is subjected to oil removal, chromic nitrate, stearic acid and PEG200 are sequentially added and mixed for a reaction, and reaction liquor j is obtained; and evaporating, drying, crushing, calcining and grinding the reaction liquid j to obtain the copper chromite black pigment.

Description

Technical Field

[0001] The invention belongs to the field of chemical technology, and further to the field of fine chemical technology, and specifically relates to a method for preparing copper chrome black pigment by recycling waste organic silicon contacts in organic silicon production. Background Art

[0002] Organosilicon is known as industrial MSG, and its impact on industry and our daily life is increasing day by day. In the production process of organosilicon, silicon and methyl chloride are used as raw materials, and ternary copper catalyst (main catalyst) and zinc (auxiliary agent) are often used to promote the synthesis of organosilicon monomers such as dimethyldichlorosilane, methyltrichlorosilane, trimethylchlorosilane, methyldichlorosilane, etc. In the synthesis process, pulp residue and waste contacts are generated.

[0003] The main components of waste contacts are silicon, copper, carbon, zinc, etc., and their weight contents in waste contacts are 65% to 80%, 3% to 20%, 1% to 10%, and 0.05% to 2.0% respectively. Due to the fine particles and high activity of copper powder, waste contacts are prone to oxidation reaction when exposed to air, causing the organic matter and carbon in them to burn and emit pungent white smoke, making them difficult to store; pulp residue is a liquid-solid mixture with fluidity obtained by wet dust removal process in the direct synthesis of methylchlorosilane. After hydrolysis, it becomes a black solid powder containing about 1-3% copper, which seriously pollutes the environment and has serious "three wastes" problems.

[0004] Copper chrome black (CuCr2O4) pigment is a metal oxide mixed phase pigment with a crystal structure. It has excellent hiding power, chemical resistance, high temperature resistance, outdoor stability and non-diffusion properties. It is often used in ceramics, enamels, coatings and plastics. Copper chrome black mainly plays a role in coloring and corrosion protection in ceramics and enamels. Due to its excellent high temperature resistance and weather resistance, copper chrome black is widely used in outdoor steel coil coatings, and is also used in heat-resistant and weather-resistant coating systems such as fluororesins, silicones, and polyesters. It can also be used in long-lasting coatings and engineering plastics. In addition, copper chrome black also has excellent visible light responsiveness and photochemical stability. It has broad application prospects in photocatalytic decomposition of water to produce hydrogen and photodegradation of organic matter, such as decolorization and degradation of organic dyes such as methyl orange, acid red B, and reactive brilliant red K-2G.

[0005] The traditional methods for preparing copper chromium black mainly include solid phase method and hydroxide co-precipitation method. In the solid phase method, solid copper carbonate and sodium dichromate with high purity, or copper oxide and chromium trioxide are mixed in a certain proportion, ground into fine powder, and then placed in a calcining furnace for calcination for a period of time, and then rinsed, filtered, dried, and ground to obtain the finished product. The hydroxide co-precipitation method is to mix the soluble salt solution of copper and chromium in a certain proportion, and then add alkali for co-precipitation. The precipitate is rinsed, filtered, dried, and then calcined in a calcining furnace to obtain the product. In addition, there are hydrothermal method, microemulsion method and sol-gel method. The solid phase method for preparing copper chromium black has the following problems: (1) Since the raw materials are solid, even after a long period of grinding and mixing, they are not uniform, resulting in a small contact area between the reactant particles, low reaction activity, and uneven and insufficient reaction; (2) In order to make the reaction sufficient and uniform, the reaction temperature is relatively high, generally around 1200°C, which consumes a lot of energy and causes serious pigment agglomeration, coarse particles and uneven distribution; (3) In order to meet the particle size requirements of the application, it is often necessary to grind again, which can easily cause lattice damage, bring impurities, and reduce its chemical resistance. The raw materials of the hydroxide coprecipitation method require soluble salts, such as nitrates and sulfates of copper and chromium, which have higher requirements; the production process is relatively complicated, the product particles are coarse and the particle distribution is uneven, and the product purity is not high. Other chemical methods, such as hydrothermal method, microemulsion method and sol-gel method, also have high requirements for raw materials, complex process, often require high temperature and high pressure, high requirements for equipment, long reaction time, high production cost, and are not conducive to industrial production. Summary of the invention

[0006] The object of the present invention is to provide a method for preparing copper chrome black pigment by recycling waste organic silicon contacts in organic silicon production.

[0007] The object of the present invention is achieved by comprising pre-treatment, acid leaching, water leaching and post-treatment steps, specifically comprising: A. Pretreatment: Add water to the waste organic silicon contact body in the production of the to-be-treated organic silicon, stir and leach, and then filter press to obtain filtrate a and filter residue b; leach the copper ions dissolved in water in the waste organic silicon contact body into the aqueous solution to reduce the acid consumption of the filter residue acid leaching.

[0008] B. Acid leaching: grind the filter residue b and add concentrated sulfuric acid for acid leaching to obtain acid leached material c; dissolve the copper ions of the waste organosilicon contact body in sulfuric acid and leach them into the solution.

[0009] C. Water immersion: The acid leaching material c is incorporated into the filtrate a for water immersion to facilitate subsequent filter pressing to obtain the filtrate d and filter residue e. The filter residue e is the silicon powder and enters the organic silicon production system; the acid leaching material c is incorporated into the filtrate a for water immersion.

[0010] D. Post-processing: 1) P204 is added to the filtrate d to extract copper, and the extraction is performed to obtain P204 extract f and extracted liquid g; 2) Add sulfuric acid to the P204 extract to perform stripping to obtain stripping solution h and raffinate i. P204 has good selectivity for copper, and P204 is easy to separate from the aqueous phase; it is easy to recycle and reuse. Therefore, the extractant is selected as P204 (chemical name is di(2-ethylhexyl)phosphoric acid, which is an organic weak acid), and then washed with low-concentration sulfuric acid, and copper is stripped with sulfuric acid to obtain pure copper sulfate stripping solution. In order to completely regenerate P204 that has been loaded with impurities (such as iron, zinc, etc.), high-concentration sulfuric acid is used for washing and stripping; 3) After deoiling the stripping solution h, chromium nitrate, stearic acid and PEG200 are added in sequence, mixed and reacted to obtain a reaction solution j; 4) The reaction solution j is evaporated, dried, crushed, calcined and ground to obtain copper chrome black pigment.

[0011] The beneficial effects of the present invention are as follows: Waste silicone contacts in silicone production are mainly silicon powder containing various heavy metals and other impurities. According to the characteristics of copper, zinc, silicon and other elements and their compounds in the silicon powder, after leaching, extraction and degreasing of stripping solution, a solution mixed with chromium nitrate, stearic acid and PEG200 is added, evaporated, dried, crushed, burned, calcined and ground to obtain high-attachment copper chrome black pigment. This process technology has flexible process conditions and can be used for resource utilization of waste silicone contacts in silicone production by effectively improving the leaching property of copper metal and the filterability of silicon powder to obtain high-value copper chrome black pigment. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the process flow of the present invention. DETAILED DESCRIPTION

[0013] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0014] The method for preparing copper chrome black pigment by recycling waste organic silicon contacts in organic silicon production of the present invention comprises pre-treatment, acid leaching, water leaching and post-treatment steps, specifically comprising: A. Pretreatment: Add water to the waste organic silicon contact body in the production of the to-be-treated organic silicon, stir and leach, and then filter press to obtain filtrate a and filter residue b; leach the copper ions dissolved in water in the waste organic silicon contact body into the aqueous solution to reduce the acid consumption of the filter residue acid leaching.

[0015] B. Acid leaching: grind the filter residue b and add concentrated sulfuric acid for acid leaching to obtain acid leached material c; dissolve the copper ions of the waste organosilicon contact body in sulfuric acid and leach them into the solution.

[0016] C. Water immersion: The acid leaching material c is incorporated into the filtrate a for water immersion to facilitate subsequent filter pressing to obtain the filtrate d and filter residue e. The filter residue e is the silicon powder and enters the organic silicon production system; the acid leaching material c is incorporated into the filtrate a for water immersion.

[0017] D. Post-processing: 1) P204 is added to the filtrate d to extract copper, and the extraction is performed to obtain P204 extract f and extracted liquid g; 2) Add sulfuric acid to the P204 extract to perform stripping to obtain stripping solution h and raffinate i. P204 has good selectivity for copper, and P204 is easy to separate from the aqueous phase; it is easy to recycle and reuse. Therefore, the extractant is selected as P204 (chemical name is di(2-ethylhexyl)phosphoric acid, which is an organic weak acid), and then washed with low-concentration sulfuric acid, and copper is stripped with sulfuric acid to obtain pure copper sulfate stripping solution. In order to completely regenerate P204 that has been loaded with impurities (such as iron, zinc, etc.), high-concentration sulfuric acid is used for washing and stripping; 3) After deoiling the stripping solution h, chromium nitrate, stearic acid and PEG200 are added in sequence, mixed and reacted to obtain a reaction solution j; 4) The reaction solution j is evaporated, dried, crushed, burned, calcined and ground to obtain copper chrome black pigment.

[0018] The amount of water added in step A is 2 to 6 times the mass of the waste silicone contact body in the production of silicone.

[0019] The acid leaching time in step B is 0.5~2h.

[0020] The acid leaching temperature in step B is 75~90℃.

[0021] D. The mass ratio of chromium nitrate, stearic acid and PEG200 described in step 3) is (90-120): (150-250): (50-90).

[0022] The present invention is further described below with specific implementation cases: Example 1 Take 1 kg of waste silicone contact body, add water and stir according to the mass ratio of water: waste silicone contact body = 4:1, then filter by pressure. Grind the filter residue for 40 minutes, leaching with concentrated sulfuric acid for 1.5 hours, leaching temperature 85°C, then merge into the water-soaked waste silicone contact body liquid and filter to obtain silicon powder, which can be returned to the silicone production system, extract copper with P204 after leaching, and back-extract the P204 extract with sulfuric acid, remove oil from the back-extracted liquid and the raffinate to obtain copper sulfate solution, add 105 g of chromium nitrate, and then add 200 g of stearic acid and 70 g of PEG200 to mix, keep the temperature at 88°C, and stir continuously until the mixed solution gradually turns into a green transparent sol, and then evaporate the water to turn into a dark green gel. The obtained gel is placed in an electric hot air drying oven and dried at 120°C for 2 hours to prepare a dry gel precursor. The obtained dry gel precursor was ground and placed in a muffle furnace, calcined at 800°C in an air atmosphere to form a gray-black powder, kept warm for 3.5 hours, taken out of the furnace and cooled, and ground to obtain a copper chromium black product. The analysis results of the copper chromium black product prepared in this example are shown in Tables 1, 2 and 3.

[0023] Example 2 Take 1 kg of waste silicone contact body, add water and stir according to the mass ratio of water: waste silicone contact body = 3:1, then filter by pressure. Grind the filter residue for 30 minutes, leaching with concentrated sulfuric acid for 1 hour, leaching temperature 80°C, then merge into the water-soaked waste silicone contact body liquid and filter to obtain silicon powder, which can be returned to the organic silicon production system, extract copper with P204 after leaching, and back-extract the P204 extract with sulfuric acid, remove oil from the back-extracted liquid and the raffinate to obtain copper sulfate solution, add 105 g of chromium nitrate, and then add 200 g of stearic acid and 70 g of PEG200 to mix, keep the temperature at 88°C, and stir continuously until the mixed solution gradually turns into a green transparent sol, and then evaporate the water to turn into a dark green gel. The obtained gel is placed in an electric hot air drying oven and dried at 120°C for 2 hours to prepare a dry gel precursor. The obtained dry gel precursor was ground and placed in a muffle furnace, calcined at 800°C in an air atmosphere to form a gray-black powder, kept warm for 3.5 hours, taken out of the furnace and cooled, and ground to obtain a copper chromium black product. The analysis results of the copper chromium black product prepared in this example are shown in Tables 1, 2 and 3.

[0024] Example 3 Take 1 kg of organic silicon waste contact body, add water and stir according to the mass ratio of water: organic silicon waste contact body = 6:1, filter by pressure after stirring. Grind the filter residue for 20 minutes, leaching with concentrated sulfuric acid for 0.5 hours, leaching temperature 75℃, then merge into water-soaked organic silicon waste contact body liquid and filter to obtain silicon powder, which can be returned to the organic silicon production system, extract copper with P204 after leaching, and back-extract the P204 extract with sulfuric acid, remove oil from the back-extracted liquid and the raffinate to obtain copper sulfate solution, add 105g of chromium nitrate, and then add 200g of stearic acid and 70g of PEG200 to mix, keep the temperature at 88℃, and stir continuously until the mixed solution gradually turns into a green transparent sol, and then evaporate the water to turn into a dark green gel. The obtained gel is placed in an electric hot air drying oven and dried at 120℃ for 2h to prepare a dry gel precursor. The obtained dry gel precursor was ground and placed in a muffle furnace, calcined at 800°C in an air atmosphere to form a gray-black powder, kept warm for 3.5 hours, taken out of the furnace and cooled, and ground to obtain a copper chromium black product. The analysis results of the copper chromium black product prepared in this example are shown in Tables 1, 2 and 3.

[0025] Example 4 Take 1 kg of waste silicone contact body, add water and stir according to the mass ratio of water: waste silicone contact body = 2:1, then filter by pressure. Grind the filter residue for 50 minutes, leaching with concentrated sulfuric acid for 2 hours, leaching temperature 90 ° C, then merge into the water-soaked waste silicone contact body liquid and filter to obtain silicon powder, which can be returned to the organic silicon production system, extract copper with P204 after leaching, and back-extract the P204 extract with sulfuric acid, remove oil from the back-extracted liquid and the raffinate to obtain copper sulfate solution, add 105 g of chromium nitrate, and then add 200 g of stearic acid and 70 g of PEG200 to mix, keep the temperature at 88 ° C, and keep stirring until the mixed solution gradually turns into a green transparent sol, and then evaporate the water to turn into a dark green gel. The obtained gel is placed in an electric hot air drying oven and dried at 120 ° C for 2 hours to prepare a dry gel precursor. The obtained dry gel precursor was ground and placed in a muffle furnace, calcined at 800°C in an air atmosphere to form a gray-black powder, kept warm for 3.5 hours, taken out of the furnace and cooled, and ground to obtain a copper chromium black product. The analysis results of the copper chromium black product prepared in this example are shown in Tables 1, 2 and 3.

[0026] Table 1 Energy spectrum analysis results

[0027] Table 2 Product particle size and distribution

[0028] Table 3 Product performance indicators .

Claims

1. A method for recycling waste organic silicon contacts in organic silicon production to prepare copper chrome black pigment, characterized in that: It includes pre-treatment, acid leaching, water leaching and post-treatment steps, specifically including: A. Pretreatment: adding water to the waste organic silicon contact body in the production of organic silicon to be treated, stirring and leaching, and then filtering by pressure to obtain filtrate a and filter residue b; B. Acid leaching: grind the filter residue b and add concentrated sulfuric acid to carry out acid leaching to obtain acid leaching material c; C. Water leaching: The acid leaching material c is incorporated into the filtrate a for water leaching to facilitate subsequent filter pressing to obtain the filtrate d and the filter residue e. The filter residue e is the silicon powder, which enters the organic silicon production system; the acid leaching material c is incorporated into the filtrate a for water leaching; D. Post-processing: 1) Adding P204 extractant to the filtrate d for extraction to obtain P204 extract f and extracted liquid g; 2) adding sulfuric acid to the P204 extract for stripping to obtain stripping solution h and raffinate i; 3) After deoiling the stripping solution h, chromium nitrate, stearic acid and PEG200 are added in sequence, mixed and reacted to obtain a reaction solution j; 4) The reaction solution j is evaporated, dried, crushed, calcined and ground to obtain copper chrome black pigment.

2. The method for preparing copper chrome black pigment by recycling waste organic silicon contacts in organic silicon production according to claim 1, characterized in that: The amount of water added in step A is 2 to 6 times the mass of the waste silicone contact body in the production of silicone.

3. The method for preparing copper chrome black pigment by recycling waste organic silicon contacts in organic silicon production according to claim 1, characterized in that: The acid leaching time in step B is 0.5~2h.

4. The method for preparing copper chrome black pigment by recycling waste organic silicon contacts in organic silicon production according to claim 1, characterized in that: The acid leaching temperature in step B is 75~90℃.

5. The method for preparing copper chrome black pigment by recycling waste organic silicon contacts in organic silicon production according to claim 1, characterized in that: D. The mass ratio of chromium nitrate, stearic acid and PEG200 described in step 3) is (90-120): (150-250): (50-90).

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