Chrome recycling method for chrome tanned sludge
A technology of chromium recovery and chrome tanning, which is applied in sludge treatment, chemical instruments and methods, chromate/dichromate, etc., can solve the problems of chromium-containing sludge polluting the environment, and achieve high promotion value and easy treatment Effect, time and cost reduction effect
Inactive Publication Date: 2017-12-29
SHANDONG AGRICULTURAL UNIVERSITY
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Problems solved by technology
[0003] Aiming at the many deficiencies in the prior art, the present invention firstly provides a method for recycling chromium from chrome tanned sludge. The method selects the acid leaching method to extract the chromium in the sludge, and then reclaims it with a high-efficiency precipitation method, and then uses h 2 o 2 Precipitate after oxidation, and finally H 2 S0 4 Acidification, creating a "H 2 S0 4 Leach-NaOH Precipitate-H 2 o 2 Oxygen-H 2 S0 4 Acidification" chromium-containing sludge recycling process system, completely solves the environmental pollution problem of chromium-containing sludge, and at the same time prepares chromium salts with economic value
Method used
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Experimental program
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Effect test
Embodiment Construction
[0025] A method for recycling chromium from chrome tanning sludge, the specific steps are as follows:
[0026] (1) Chrome tanning sludge treatment:
[0027] Grind the dry sludge into fine particles, pass through a 10-mesh sieve, mix evenly, dry to constant weight, and measure it with a spectrophotometer after full digestion. Each gram of sludge contains 170mg of chromium, of which Cr 3+ : 169.4631mg, Cr 6+ : 0.5369mg;
[0028] (2) Pickling:
[0029] Using different volumes of sulfuric acid solution, dosage of chromium-containing sludge, temperature and leaching time as variables, an orthogonal experiment was designed to optimize the single acid leaching conditions. The results showed that the combinations of conditions with the highest chromium leaching rate were: concentration of sulfuric acid The chromium leaching rate is 79.10% under the conditions of 0.75mol / L, solid-liquid ratio 15g / L, temperature 40°C, shaking time 60min; sulfuric acid concentration 1.25mol / L, solid-l...
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Abstract
The invention belongs to the field of environmental protection, and relates to a chrome recycling method for chrome tanned sludge. According to the method, chrome in the sludge is extracted by an acid leaching method, then recycled by an efficient precipitation method, oxidized by H2O2, precipitated and finally acidized by H2SO4, a chrome containing sludge recycling process system of 'H2SO4 leaching-NaOH precipitation-H2O2 oxidization-H2SO4 acidification' is built, the problem of environmental pollution caused by chrome containing sludge is thoroughly solved, and chrome salt with economic values is prepared.
Description
Technical field: [0001] The invention belongs to the field of environmental protection production, specifically relates to a clean production technology in the leather industry, and more specifically relates to a method for recycling chrome from chrome tanning sludge. Background technique: [0002] The chrome tanning wastewater of leather production industry contains high concentration of chromium, and it is required to be pretreated to make the chromium concentration meet the discharge standard required by the state before it can be mixed with wastewater generated from other production process sections for joint treatment. The chrome tanning wastewater produced by the leather industry is mainly pretreated by adding alkali and precipitation, which leads to a large amount of chromium-containing sludge. Metal chromium is the main pollutant in industrial wastewater and sludge. The random discharge of chrome tanning wastewater will cause chromium salts to accumulate in soil, pla...
Claims
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IPC IPC(8): C02F11/00C01G37/14C02F101/22
CPCC01G37/14C02F11/00C02F2101/22
Inventor 付伟章耿淑英郑书联王静
Owner SHANDONG AGRICULTURAL UNIVERSITY