Central South University

Zhang Lin

Yanjie Liang

Xu Yan

Xueming Liu

Hui Liu

Liyuan Chai

Qingwei Wang

Xiaobo Min

Qingzhu Li

Huimin Yi

Le Lin

Weichun Yang

Lin Wu

Yong Ke

Fangfang Zhu

Chen Tian

Haiying Wang

Zhangbin Liu

Kaisong Xiang

Fenghua Shen

Fandongkun Meng

Xudong Liu

The present invention provides a method for analysis and determination of the heavy metal occurrence key mineral phases in industrial solid waste, by performing N concentration gradients dissociation determination of the heavy metal solid waste to be tested under the same dissociation conditions, to give the dissociation degrees of the heavy metal elements to be tested at N different concentration gradients; the dissociated solid residues after dissociation being quantitatively analyzed for the mineral phase, to give the relative content of each mineral phase in the M mineral phases of the heavy metal solid waste to be tested; then calculating to give the occurrence distribution proportion of the heavy metal elements in the mineral phase, which are accumulated from high to low; the occurrence key mineral phase whose cumulative occurrence proportion exceeds the preset cumulative threshold value is determined to be the key mineral phase of the heavy metal elements.

Method for analysis and determination of heavy metal occurrence key mineral phases in industrial solid waste

A method for preparing hydrogen sulfide from sulfur dioxide by electrochemical reduction includes electrochemically reducing sulfur dioxide absorbed in an aqueous solution into gaseous hydrogen sulfide with a membrane electrode, resulting in efficient and selective conversion of the sulfur dioxide absorbed in the aqueous solution into the hydrogen sulfide to avoid a deactivation of a cathode due to colloidal sulfur produced on the cathode and adhesion onto a surface of the cathode, wherein the method is carried out at ambient temperature and normal pressure without addition of a reducing agent, having no waste salts produced, and is simple in operation, and is convenient for large-scale application.

Method for preparing hydrogen sulfide from sulfur dioxide by electrochemical reduction

The present invention provides a method for treating a copper-containing waste etching solution, which includes: preparing basic copper chloride nanometer seed crystals and synthesizing basic copper chloride mono-crystals; making an acidic waste etching solution subjected to agglomeration reaction with an ammonium-containing solution and slurry containing the basic copper chloride mono-crystals to obtain basic copper chloride crystal particles and copper-removed waste solution; making an alkaline waste etching solution react with sulfuric acid to obtain a copper sulfate mixed solution; and then evaporating, concentrating, cooling and crystallizing the copper sulfate mixed solution obtained by the reaction of the alkaline waste etching solution and the sulfuric acid in sequence to obtain copper sulfate pentahydrate solids. In a case of low investment, the present invention not only can realize the recycling of copper in the copper-containing waste etching solution, but also can obtain various high-value products, and can achieve both environmental and economic benefits.

Method for treating copper-containing waste etching solution

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Changsha, China

Zhang Lin