CN102718261A - Process for preparing sodium chromate by acid dissolution and oxidation of chromite - Google Patents

Abstract

The invention discloses a process for preparing sodium chromate by acid dissolution and oxidation of chromite. The process includes that the chromite is oxidized into hexavalent chromium by acid dissolution, and the hexavalent chromium is extracted from mixed solution to obtain the sodium chromate. In addition, other chemical constituents in the chromite can be extracted to prepare chemical series products by the process. The whole process is free of slags and secondary pollution, clean, energy-saving and environment-friendly, and economic and social benefits can be greatly improved for enterprises.

Description

Chromite oxidation system Sodium chromate-51Cr technology is dissolved in acid

Technical field

The present invention relates to a kind of acid and dissolve chromite oxidation system Sodium chromate-51Cr technology, belonging to the chromite is raw material, becomes sexavalent chrome through adding sour dissolved oxygen, directly produces the technical field of Sodium chromate-51Cr.

Background technology

Chromium salt production is since being born; General adopt several kinds of working methods: calcium roasting, few calcium roasting, calcium-free roasting, the inferior fused salt liquid phase oxidation style of potassium system, the tower continuous liquid phase oxidation of pneumatic fluidisation etc. are arranged, and these methods all are that to adopt with the chromite be that raw material is through roasting or add the alkali high-temperature oxidation and produce Sodium chromate-51Cr.In fact all to have the shortcoming of a maximum be exactly that the chromium slag that produces of production process is handled difficult problem to all these methods of producing chromic salts.

The chromium quantity of slag that has the calcium roasting to produce is big, and environmental pollution is big, eliminates or bans use of.The chromium slag that no calcium or few calcium roasting produce; Treatment process generally adopts: a part is returned the usefulness as the chromium salt production roasting; Another part is used for ferrochrome production, and one ton of chromium slag of every processing just loses more than 1,000 yuan, also has the chromium slag muck that partly is untreated to put; The chromium quantity of slag of accumulating over a long period increases severely, and environment is caused tremendous influence.

The chromium slag that the inferior fused salt liquid phase oxidation style of potassium system, the tower continuous liquid phase oxidation of pneumatic fluidisation produce also needs to handle, and is used to smelt behind ferrochrome or the high-temperature detoxification as the usefulness of manufacture of cement additive, and treatment capacity is limited; Have high input; Highly energy-consuming is prone to environment is produced secondary pollution, and loss is big.

Disclosed Chinese invention patent " is produced the method for Sodium chromate-51Cr " through calcium-free roasting by chromite, the patent No.: 200710017747.8, and publication number: CN101045559, open day: there was above problem in 2007.10.03.

Summary of the invention

The objective of the invention is to adopt a kind of novel chromium salt production method, reach the purpose of efficient, energy-conservation, cleaning, environmental protection, no slag, create best business economic benefit and social benefit.

The object of the invention reaches through following measure:

Chromite oxidation system Sodium chromate-51Cr technology is dissolved in a kind of acid; It is characterized in that, be that raw material adds sour dissolved oxygen and produces Sodium chromate-51Cr with the chromite, and other material in the chromite is extracted direct production go out series chemical product; Whole process flow does not have the slag discharging, the steps include:

1. chromite being pulverized is 200 orders, and adding hydrochloric acid, nitric acid, sulfuric acid, perchloric acid intensification oxidation become sexavalent chrome, add entry and make soluble substance become ion, and the solution metal ion is: Cr ⁶⁺, Fe ³⁺, AI ³⁺, Mg ²⁺, throw out is: Cr ₂O ₃, SiO ₂, Fe ₂O ₃And AI ₂O ₃

2. discharge solution, throw out filter, washing, separate, and drying makes product F e ₂O ₃And Cr ₂O ₃, SiO ₂And AI ₂O ₃Mix product;

3. mixing solutions (Cr ⁶⁺, Fe ³⁺, AI ³⁺, Mg ²⁺) middle NaOH or KOH or the NH of adding ₃.H ₂O makes Fe ³⁺Be precipitated as Fe (OH) fully ₃, discharge solution, throw out to be filtered, washs, drying makes Fe (OH) ₃Product;

4. mixing solutions (Cr ⁶⁺, AI ³⁺, Mg ²⁺) middle NaOH or KOH or the NH of adding ₃.H ₂O makes AI ³⁺Be precipitated as AI (OH) fully ₃, discharge solution, throw out to be filtered, washs, drying makes AI (OH) ₃Product;

5. mixing solutions (Cr ⁶⁺, Mg ²⁺) the middle BaCI that adds ₂Or Ba (OH) ₂Or Ba (NO ₃) ₂, make Cr ⁶⁺Be precipitated as BaCrO fully ₄, discharge solution, throw out to be filtered, washs, drying makes BaCrO ₄Product;

6. add NaOH or KOH or NH in the mixing solutions ₃.H ₂O makes Mg ²⁺Be precipitated as Mg (OH) fully ₂, discharge solution, throw out to be filtered, washs, drying makes Mg (OH) ₂Product;

7. filtrating whiz or crystallization make product sodium salt or sylvite or ammonium salt;

8. with BaCrO ₄The middle H that adds ₂SO ₄Dissolving generates BaSO ₄Deposition and H ₂CrO ₄Solution is discharged H ₂CrO ₄Solution filters, washs, and drying makes BaSO ₄Product;

9.H ₂CrO ₄Add the NaOH complete reaction in the solution, put into spray-dryer, drying makes Na ₂CrO ₄Product;

Embodiment

In order to realize the feasibility of this invention, on April 18th, 2012, carry out implementation and operation:

1. get chromite 500g and wear into 200 orders and put into the 10L reaction kettle, added hydrochloric acid, nitric acid, sulfuric acid mixed solution 2000g stirring reaction 2 hours, add perchloric acid 60g and be heated to and smolder, stop heating, cooling;

2. add 3000g water stirring and dissolving, filtration, washing, drying make mixture 65g;

3. add 98%NaOH in the yellow filtrate, make Fe ³⁺Be precipitated as Fe (OH) fully ₃, discharge solution, with throw out filtration, washing, drying, make product F e (OH) ₃85g;

4. add 98%NaOH in the filtrating and make AI ³⁺Be precipitated as AI (OH) fully ₃, discharge solution, with throw out filtration, washing, drying, make product A I (OH) ₃110g;

5. add BaCI in the filtrating ₂1400g stirs, and makes Cr ⁶⁺Be precipitated as BaCrO fully ₄, discharge solution, with throw out filtration, washing, drying, make product B aCrO ₄510g;

6. add 98%NaOH in the filtrating and make Mg ²⁺Be precipitated as Mg (OH) fully ₂, discharge solution, with throw out filtration, washing, drying, make product Mg (OH) ₂96g;

7. with BaCrO ₄The middle H that adds ₂SO ₄Dissolving generates BaSO ₄Deposition is discharged solution (H ₂CrO ₄), with throw out filtration, washing, drying, make product B aSO ₄565g;

8. (H in filtrating ₂CrO ₄) add the 99.5%NaOH complete reaction, solution is put into spray-dryer carry out drying, make product Na ₂CrO ₄262g.

Facts have proved this and invent whole chrominm salt production technology flow process, the chromite utilization ratio is high, and the chemical substance in the chromite is directly extracted produces series chemical product, and quality better is worth height, the huge market demand.The less investment low power consuming, production process non-secondary pollution, no slag discharging, cleaning, energy-saving and environmental protection.Have good practicability and feasibility, good economic benefit, environmental benefit and social benefit are arranged.

Claims (1)

1. chromite oxidation system Sodium chromate-51Cr technology is dissolved in an acid; It is characterized in that, be that raw material adds sour dissolved oxygen and produces Sodium chromate-51Cr with the chromite, and other material in the chromite is extracted direct production go out series chemical product; Whole process flow does not have the slag discharging, the steps include:

1. chromite being pulverized is 200 orders, and adding hydrochloric acid, nitric acid, sulfuric acid, perchloric acid intensification oxidation become sexavalent chrome, add entry and make soluble substance become ion, and the solution metal ion is: Cr ⁶⁺, Fe ³⁺, AI ³⁺, Mg ²⁺, throw out is: Cr ₂O ₃, SiO ₂, Fe ₂O ₃And AI ₂O ₃

2. discharge solution, throw out filter, washing, separate, and drying makes product F e ₂O ₃And Cr ₂O ₃, SiO ₂And AI ₂O ₃Mix product;

3. mixing solutions (Cr ⁶⁺, Fe ³⁺, AI ³⁺, Mg ²⁺) middle NaOH or KOH or the NH of adding ₃.H ₂O makes Fe ³⁺Be precipitated as Fe (OH) fully ₃, discharge solution, throw out to be filtered, washs, drying makes Fe (OH) ₃Product;

4. mixing solutions (Cr ⁶⁺, AI ³⁺, Mg ²⁺) middle NaOH or KOH or the NH of adding ₃.H ₂O makes AI ³⁺Be precipitated as AI (OH) fully ₃, discharge solution, throw out to be filtered, washs, drying makes AI (OH) ₃Product;

5. mixing solutions (Cr ⁶⁺, Mg ²⁺) the middle BaCI that adds ₂Or Ba (OH) ₂Or Ba (NO ₃) ₂, make Cr ⁶⁺Be precipitated as BaCrO fully ₄, discharge solution, throw out to be filtered, washs, drying makes BaCrO ₄Product;

6. add NaOH or KOH or NH in the mixing solutions ₃.H ₂O makes Mg ²⁺Be precipitated as Mg (OH) fully ₂, discharge solution, throw out to be filtered, washs, drying makes Mg (OH) ₂Product;

7. filtrating whiz or crystallization make product sodium salt or sylvite or ammonium salt;

8. with BaCrO ₄The middle H that adds ₂SO ₄Dissolving generates BaSO ₄Deposition and H ₂CrO ₄Solution is discharged H ₂CrO ₄Solution filters, washs, and drying makes BaSO ₄Product;

9.H ₂CrO ₄Add the NaOH complete reaction in the solution, put into spray-dryer, drying makes Na ₂CrO ₄Product.