阅读说明：本技术 一种氯化法处理含铬芒硝废盐的方法 (Method for treating chromium-containing mirabilite waste salt by chlorination process ) 是由 林璋 宿新泰 高会芹 张丽娟 于 2021-07-31 设计创作，主要内容包括：本发明属于工业废盐渣处理技术领域,公开了一种氯化法处理含铬芒硝废盐的方法。该方法包括以下步骤：将氯化剂与含铬芒硝废盐混合均匀；然后研磨；将研磨好的混合物在保护气氛下焙烧除铬。其中,焙烧的温度在450～750℃；焙烧的升温速率在5～10℃/min；焙烧的时长为1～2h。本发明的处理工艺简单、成本低、见效快、处理量大、提纯彻底,可以实现含铬芒硝废渣盐的提纯及再利用；为化工行业实现无害化提供技术支撑,促进化工行业的可持续协调发展。(The invention belongs to the technical field of industrial waste salt slag treatment, and discloses a method for treating chromium-containing mirabilite waste salt by a chlorination process. The method comprises the following steps: uniformly mixing a chlorinating agent with chromium-containing mirabilite waste salt; then grinding; and roasting the ground mixture in a protective atmosphere to remove chromium. Wherein the roasting temperature is 450-750 ℃; the temperature rise rate of roasting is 5-10 ℃/min; the roasting time is 1-2 h. The treatment process is simple, low in cost, quick in effect, large in treatment capacity and thorough in purification, and can realize the purification and reutilization of chromium-containing mirabilite waste residue; provides technical support for realizing harmlessness of the chemical industry and promotes sustainable coordinated development of the chemical industry.)

1. A method for treating chromium-containing mirabilite waste salt by a chlorination method is characterized by comprising the following steps:

(1) uniformly mixing a chlorinating agent with chromium-containing mirabilite waste salt;

(2) grinding the mixture in the step (1);

(3) and (3) roasting the mixture ground in the step (2) under a protective atmosphere to remove chromium.

2. The method for treating chromium-containing mirabilite waste salt by the chlorination process according to claim 1, wherein the chlorinating agent in step (1) is at least one selected from hydrochloric acid, ammonium chloride and hydroxylamine hydrochloride.

3. The method for treating chromium-containing mirabilite waste salt by a chlorination process according to claim 1, wherein the mass ratio of the chromium-containing mirabilite waste salt to the chlorinating agent in step (1) is 1:1 to 15: 1.

4. The method for treating chromium-containing mirabilite waste salt by the chlorination process according to claim 1, wherein the grinding time in step (2) is 10-20 min.

5. The method for treating chromium-containing mirabilite waste salt by the chlorination process as claimed in claim 1, wherein the grinding in step (2) is performed in an agate mortar.

6. The method for treating chromium-containing mirabilite waste salt by the chlorination process according to claim 1, wherein the protective atmosphere in step (3) is N₂。

7. The method for treating chromium-containing mirabilite waste salt by the chlorination process as claimed in claim 1, wherein the roasting in step (3) is performed in a porcelain boat.

8. The method for treating chromium-containing mirabilite waste salt by the chlorination process according to claim 1, wherein the roasting temperature in the step (3) is 450-750 ℃.

9. The method for treating chromium-containing mirabilite waste salt by the chlorination process according to claim 1, wherein the temperature rise rate of the roasting in the step (3) is 5-10 ℃/min.

10. The method for treating chromium-containing mirabilite waste salt by the chlorination process according to any one of claims 1 to 9, wherein the roasting time in step (3) is 1-2 hours.

Technical Field

The invention belongs to the technical field of industrial waste salt slag treatment, and particularly relates to a method for treating chromium-containing mirabilite waste salt by a chlorination process.

Background

The chromium salt industry is a very important branch of the chemical industry, is widely applied to the industries of metallurgy, electroplating, tanning, pharmacy, dye, synthetic rubber, spice, industrial catalysis, grease, metal surface treatment, military industry and the like, and is an indispensable resource raw material industry in national economy. Statistically, about 10% of the products in the national economy are associated with chromium salts. The total yield of chromium salt (calculated as sodium bichromate) in China in 2005 is about 1/4 of the total yield in the world, and the yield is continuously increasing every year. Sodium bichromate (sodium dichromate dihydrate) is an important basic product in the chromium salt industry and can be used as a raw material for producing chromic anhydride, potassium dichromate, ammonium dichromate, basic chromium sulfate, chromium oxide green and the like. The principle that trivalent chromium and protein are easy to form stable compounds is utilized, and the tanning industry is used as a tanning agent to improve the texture of leather; by utilizing the passivation effect of chromium and stronger reflection capacity to light, the electroplating and coating industries are used for passivation treatment after galvanization, so that the wear resistance of a plated part is improved, and the brightness is increased; by utilizing the special coloring capability of chromium ions, the glass industry is used as a green colorant, and the service performance of glass is improved.

The chromium-containing mirabilite is a byproduct in the chemical production process of chromium salt, and sodium sulfate (with Na) in the chromium-containing mirabilite₂SO₄Calculated as Na) content of 80-85 percent and hexavalent chromium (calculated as Na)₂Cr₂O₇·2H₂O)<0.5 percent of water and 15 to 20 percent of water. Wherein, the chromium-containing sodium sulfate contains hexavalent chromium (Cr)⁶⁺) The chromium sulfate is easy to dissolve and unstable, is soaked by rain and snow in the transportation and storage processes, and the hexavalent chromium in the chromium-containing mirabilite is slowly released into the environment, thereby not only polluting the environment, but also wasting a large amount of metal chromium resources. Since 2000, researches on reuse of chromium-containing mirabilite have been gradually emerging. A method for refining anhydrous sodium sulphate from chromium-containing mirabilite has been developed by Lipiong, Mashui, Baili and Huyi Hua (CN 103539164A). The method adopts a crystal slurry method to produce the anhydrous sodium sulphate, but the hexavalent chromium in the produced anhydrous sodium sulphate exceeds the standard due to the problem that the hexavalent chromium is wrapped by the crystal slurry. In addition, sulfurous acid is used in the methodSodium is used as a reducing agent, sodium hydroxide is used as a neutralizing agent, and the two raw materials are too expensive for the low-value product anhydrous sodium sulphate, so that the production cost of the anhydrous sodium sulphate is higher, and the actual productivity cannot be realized. A method (CN 107934993B) for preparing anhydrous sodium sulfate by using chromium-containing mirabilite is developed by the eastern certified chemical industry, national county, Shanxi province, and the market competitiveness cannot be formed because the hydrothermal method reduction process is adopted, the equipment investment is increased, and the requirement of treating chromium-containing mirabilite waste salt in a large batch cannot be met.

Disclosure of Invention

Aiming at the defects and shortcomings of the prior art, the invention aims to provide a method for treating chromium-containing mirabilite waste residue salt by a chlorination process. The method has the advantages of simple process, low cost, quick response, large treatment capacity and thorough purification, and can realize the purification and reutilization of the chromium-containing mirabilite waste residue. The chromium extracted by the method can be collected and reused in the production industry of chromium salt products or used for preparing chromium-containing catalytic materials and the like. The sodium sulfate extracted by the method can be recycled for production process or can be used for manufacturing glass, porcelain glaze, refrigerating mixers and the like, thereby changing waste into valuable.

The purpose of the invention is realized by the following technical scheme:

a method for treating chromium-containing mirabilite waste salt by a chlorination method comprises the following steps:

(1) uniformly mixing a chlorinating agent with chromium-containing mirabilite waste salt;

(2) grinding the mixture in the step (1);

(3) and (3) roasting the mixture ground in the step (2) under a protective atmosphere to remove chromium.

Preferably, the chlorinating agent in the step (1) is at least one selected from hydrochloric acid, ammonium chloride and hydroxylamine hydrochloride.

Preferably, the mass ratio of the chromium-containing mirabilite waste salt to the chlorinating agent in the step (1) is 1:1 to 15: 1.

Preferably, the grinding time in the step (2) is 10-20 min.

Preferably, the grinding in step (2) is carried out in an agate mortar.

Preferably, the step (3) is performed byThe protective atmosphere is N₂。

Preferably, the firing in step (3) is performed in a porcelain boat.

Preferably, the roasting temperature in the step (3) is 400-750 ℃.

Preferably, the temperature rise rate of the roasting in the step (3) is 5-10 ℃/min.

Preferably, the roasting time in the step (3) is 1-2 h.

The principle of the invention is as follows:

the high reactivity of chlorine is utilized, corresponding chloride can be formed almost with all metals, and selective separation and recovery are carried out by utilizing the difference of vapor pressure of metal chloride, so that the purposes of separating and recovering heavy metal impurities and purifying are achieved. Chlorination has proven to be an effective method for extracting heavy metals and rare and precious metals. The chlorination process has been studied in the solid waste treatment field, and can be classified into tailing solid waste, electronic solid waste, municipal solid waste and industrial solid waste according to the type of solid waste.

The treatment method of the invention has the following advantages and beneficial effects:

(1) the metal Cr in the waste salt slag is efficiently and thoroughly chloridized by chloridizing roasting, so as to achieve the purpose of purifying the mirabilite (sodium sulfate).

(2) The Cr metal element which is recycled can be recovered, and the sustainable coordinated development of the chemical industry is promoted.

(3) The method can realize resource utilization of mirabilite waste residue and salt, and has no pollution discharge.

Drawings

FIG. 1 is a diagram of a chromium-containing waste salt of mirabilite used in examples 1,2,3,4, and 5 of the present invention.

FIG. 2 is an XRD pattern of chromium-containing glauber's salt waste material used in examples 1,2,3,4 and 5 of the present invention.

FIG. 3 is a diagram showing a sample after chlorination treatment in example 5 of the present invention.

Detailed Description

The present invention will be described in further detail with reference to examples, but the embodiments of the present invention are not limited thereto.

Example 1

(1) Adding 3.0000g ammonium chloride (mass ratio of 1:1) into 3.0000g chromium-containing Natrii sulfas waste salt (shown in figure 1 and figure 2) at normal temperature and pressure, grinding for 10min, and mixing;

(2) transferring the well mixed mixture to a porcelain boat, N₂Keeping the temperature for 2h at 450 ℃ at the heating rate of 5 ℃/min under the atmosphere of protective gas.

Example 1 3 grams of chromium-containing glauber salt waste was processed and 5.0012 grams of sodium sulfate was recovered, wherein the excess ammonium chloride did not allow a defined yield. The total Cr content in the roasted product is reduced from 0.1212mg/g to 0.0968 mg/g. The product is tested to II class first-class standard in GB/T6009-2014 industry anhydrous sodium sulfate standard.

Example 2

(1) Adding 3.0000g ammonium chloride (mass ratio 1:1) into 3.0000g chromium-containing Natrii sulfas waste salt (shown in figure 1 and figure 2) at normal temperature and pressure, grinding for 10min, and mixing;

(2) transferring the well mixed mixture to a porcelain boat, N₂Keeping the temperature for 2h at 450 ℃ at a heating rate of 10 ℃/min under the atmosphere of protective gas.

Example 23 g of chromium-containing mirabilite waste salt was treated, 5.0025g of sodium sulfate was recovered, and the total Cr content in the roasted product was reduced from 0.1212mg/g to 0.0889 mg/g. The product is tested to II class first-class standard in GB/T6009-2014 industry anhydrous sodium sulfate standard.

Example 3

(1) Adding 0.3004g ammonium chloride (mass ratio is 10:1) into 3.0019g chromium-containing mirabilite waste salt (shown in figure 1 and figure 2) at normal temperature and normal pressure, grinding for 10min, and mixing uniformly;

(2) transferring the well mixed mixture to a porcelain boat, N₂Keeping the temperature for 2h at 450 ℃ at a heating rate of 10 ℃/min under the atmosphere of protective gas.

Example 3 3.0019g of chromium-containing glauber salt waste salt were processed and 2.6956g of sodium sulfate was recovered, wherein the yield was 81.62%. The total Cr content in the roasted product is reduced from 0.1212mg/g to 0.0617 mg/g. The product is tested to II class first-class standard in GB/T6009-2014 industry anhydrous sodium sulfate standard.

Example 4

(1) Adding 0.2003g ammonium chloride (mass ratio 15:1) into 3.0032g chromium-containing mirabilite waste salt (shown in figure 1 and figure 2) at normal temperature and normal pressure, grinding for 10min, and mixing uniformly;

(2) transferring the well mixed mixture to a porcelain boat, N₂Keeping the temperature for 2h at 450 ℃ at a heating rate of 10 ℃/min under the atmosphere of protective gas.

Example 4 3.0032g of chromium-containing glauber salt waste salt were processed and 2.7063g of sodium sulfate was recovered, wherein the yield was 84.48%. The total Cr content in the roasted product is reduced from 0.1212mg/g to 0.0334 mg/g. The product is tested to II class first-class standard in GB/T6009-2014 industry anhydrous sodium sulfate standard.

Example 5

(1) Adding 0.3008g ammonium chloride (mass ratio is 10:1) into 3.0037g chromium-containing mirabilite waste salt (shown in figure 1 and figure 2) at normal temperature and normal pressure, grinding for 10min, and mixing uniformly;

(2) transferring the well mixed mixture to a porcelain boat, N₂Keeping the temperature for 2h at the temperature rising rate of 10 ℃/min 550 ℃ under the atmosphere of protective gas.

The graph of the sample after chlorination in example 5 is shown in fig. 3, the color changes from yellow green (fig. 1) to white (fig. 3), the total content is detected by inductively coupled plasma spectroscopy (ICP-OES), the chromium removal efficiency is 76.23%, 3.0037g of waste salt containing chromium mirabilite is treated in this example, 2.7079g of sodium sulfate is recovered, and the yield is 81.95%. The total Cr content in the roasted product, 0.1212mg/g, was reduced to 0.0288 mg/g. The product is tested to II class first-class standard in GB/T6009-2014 industry anhydrous sodium sulfate standard.

Example 6

(1) Adding 0.3008g ammonium chloride (mass ratio is 10:1) into 3.0028g chromium-containing mirabilite waste salt (shown in figure 1 and figure 2) at normal temperature and normal pressure, grinding for 10min, and mixing uniformly;

(2) transferring the well mixed mixture to a porcelain boat, N₂Keeping the temperature for 2h at the temperature rising rate of 10 ℃/min 750 ℃ under the atmosphere of protective gas.

Example 6 3.0028g of chromium-containing mirabilite waste salt were processed and 2.7459g of sodium sulfate was recovered, wherein the yield was 81.95%. The total Cr content in the roasted product, 0.1212mg/g, was reduced to 0.0458 mg/g. The product is tested to II class first-class standard in GB/T6009-2014 industry anhydrous sodium sulfate standard.

Example 7

(1) Adding 0.5ml 0.2MHCl into 3.0028g chromium-containing mirabilite waste salt (shown in figure 1 and figure 2) at normal temperature and normal pressure, grinding for 10min, and mixing;

(2) transferring the well mixed mixture to a porcelain boat, N₂Keeping the temperature for 2h at 450 ℃ at a heating rate of 10 ℃/min under the atmosphere of protective gas.

Example 7 treated 3.0028g of chromium-containing mirabilite waste salt and recovered 2.9756g of sodium sulfate, the total Cr content in the roasted product was reduced from 0.1212mg/g to 0.0378 mg/g. The product is tested to II class first-class standard in GB/T6009-2014 industry anhydrous sodium sulfate standard.

Example 8

(1) Grinding 3.0028g of chromium-containing mirabilite waste salt (as shown in figure 1 and figure 2)0.2998g of hydroxylamine hydrochloride (mass ratio of 10:1) at normal temperature and normal pressure for 10min and mixing uniformly;

(2) transferring the well mixed mixture to a porcelain boat, N₂Keeping the temperature for 2h at 450 ℃ at a heating rate of 10 ℃/min under the atmosphere of protective gas.

Example 8 3.0028g of chromium-containing mirabilite waste salt was treated, 2.9756g of sodium sulfate was recovered, and the total Cr content in the roasted product was reduced from 0.1212mg/g to 0.0258 mg/g. The product is tested to II class first-class standard in GB/T6009-2014 industry anhydrous sodium sulfate standard.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.