Process method for recovering chromium and aluminum by comprehensively utilizing waste aluminum residues

A process method and waste recycling technology, which is applied in the field of recycling sodium dichromate and alumina, can solve the problems of high impurity content, affecting the quality of alumina products, etc., and achieve the effects of increasing economic benefits, easy implementation of production conditions, and protecting the environment

Inactive Publication Date: 2015-07-29
CHONGQING MINFENG CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The biggest disadvantage of this method is: due to the addition of reducing agent in the step of alkali leaching aluminum, the

Method used

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  • Process method for recovering chromium and aluminum by comprehensively utilizing waste aluminum residues

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Example Embodiment

[0024] Example 1

[0025] A process method for comprehensively utilizing aluminum mud waste to recover chromium and aluminum. The specific steps are as follows:

[0026] (1) Preliminary chromium removal by beating and washing

[0027] According to the ratio of aluminum mud mass (g): water volume (ml) of 1:3, the aluminum mud is mixed with water, heated to 65° C. and kept warm, and stirred for 145 minutes at a rotation speed of 200 r / min. Centrifuge is used for solid-liquid separation, and the supernatant and sediment are collected separately, and the supernatant is returned to the chromium salt production process for recycling, and the sediment is used for further chromium removal.

[0028] (2) Electrodialysis to remove chromium

[0029] ① Design of electrodialysis device

[0030] The main body of the electrodialysis device is a rectangular parallelepiped water tank made of organic glass. The water tank is divided into three independent spaces: a cathode chamber, an intermediate chamber...

Example Embodiment

[0038] Example 2

[0039] A process method for comprehensively utilizing aluminum mud waste to recover chromium and aluminum is the same as implementation case 1, in which:

[0040] In step (1), the ratio of the mass (g) of the aluminum mud: the volume (ml) of the water is 1:2, heat to 60°C and keep it warm, and stir for 90 minutes at a rotation speed of 180r / min.

[0041] In steps (2)-②, the sediment obtained in step (1), that is, the aluminum sludge after preliminary chromium removal, is based on the ratio of the mass (g) of the aluminum sludge to the volume (ml) of water (ml) as 1:5 After being mixed evenly, it is added to the middle chamber of the electrolytic cell as the raw material for electrodialysis. A 0.1mol / L sodium sulfate solution was prepared and added to the cathode chamber and anode chamber at both ends of the electrolytic cell as the working medium. Put the electrolytic cell into a water bath heating tank, heat it to 30°C and keep it warm. Turn on the stirring dev...

Example Embodiment

[0046] Example 3

[0047] A process method for comprehensively utilizing aluminum mud waste to recover chromium and aluminum is the same as implementation case 1, in which:

[0048] In step (1), the ratio of the mass (g) of the aluminum mud: the volume (ml) of the water is 1:5, heat to 70° C. and keep it warm, and stir for 180 min at a rotation speed of 240 r / min.

[0049] In steps (2)-②, the sediment obtained in step (1), that is, the aluminum sludge after preliminary chromium removal, is based on the ratio of the mass of aluminum sludge (g) to the volume of water (ml) as 1:8 After being mixed evenly, it is added to the middle chamber of the electrolytic cell as the raw material for electrodialysis. A 1mol / L sodium sulfate solution was prepared and added to the cathode chamber and anode chamber at both ends of the electrolytic cell as the working medium. Put the electrolytic cell into a water bath heating tank, heat it to 40°C and keep it warm. Turn on the stirring device, keep t...

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Abstract

The invention provides a process method for recovering chromium and aluminum by comprehensively utilizing waste aluminum residues, and relates to a novel method for recovering sodium chromate and aluminum oxide from industrial waste chromium-containing aluminum residues. The waste chromium-containing aluminum residues serve as a raw material and are separated with beating, water washing, electroosmosis and other processes, so that the sodium chromate solution is obtained and used for producing sodium dichromate products; the aluminum residues after dechroming processing are dissolved with a NaOH solution, and then a high-purity metallurgical grade aluminum oxide product is obtained with repeated continuous carbonation decomposition methods. With the adoption of the process method, hexavent chromium in the chromium-containing aluminum residues can be recovered, valuable metal aluminum in the aluminum residues is extracted, the qualified aluminum oxide product is produced, and meanwhile, the environment is effectively protected.

Description

Technical field [0001] The invention belongs to the technical field of recovering sodium dichromate and alumina from inorganic salt industrial waste, and specifically relates to a method for recovering and producing sodium chromate and alumina from chromium aluminum waste sludge. Background technique [0002] The biggest feature of chromium salt production is that the products are poisonous and harmful, and the pollution of the three wastes is serious. Chromium-containing aluminum mud is one of the main solid wastes in the production of chromium salts. The NaAlO in the alkaline solution of sodium chromate 2 With Cr 3+ Co-precipitation to form Al(OH) 3 And Cr(OH) 3 Sediment, due to Al(OH) formed 3 And Cr(OH) 3 For flocculent amorphous sedimentation or colloidal sedimentation, a large amount of sodium chromate alkaline solution is wrapped, which is extremely difficult to filter and wash, so the loss of sodium chromate is great. A considerable amount of chromium in the chromium-cont...

Claims

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Application Information

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IPC IPC(8): C22B7/00C22B34/32C22B21/00
CPCY02P10/20
Inventor 万华龙魏顺安董立春田锡军张永红李奕辰司文青何方朱新
Owner CHONGQING MINFENG CHEM
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