###### Abstract  
Based on a \"filter press backwash-chemical precipitation-gaseous membrane absorption\" process, treatment of harmless cyanide tailings was conducted using cyanide tailings from a gold smelting enterprises (Yunnan Province, China) as the research object. The effects of air-drying time, backwash water parameters, initial pH of acidification, NaHS dosage, cyanide-containing water flow rate, and gaseous membrane stages on the process were investigated. Chemical composition, X-ray diffraction, and X-ray photoelectron spectroscopy analyses of the copper products were carried out. Results showed that the copper content in the copper product was 54.56%, and the chemical composition was mainly CuSCN, CuS, Cu\({}_{2}\)S, and CaSO\({}_{4}\). Five cycles of experiments were carried out under optimal conditions; the results showed that the process can make the treated cyanide tailings meet the requirements of the technical specification for pollution control of cyanide leaching residue in the gold industry (TSPC) standard for storage in a tailings pond and a have certain stability. The average recovery rate of copper and total cyanide in elution water was 97.8% and 99.89%, respectively, and the average removal rate of thiocyanate was 94.09%. c 2021 14 February 2021 26 February 2021 27 January 2021 27 January 2021 27 January 2021 27 February 2021 27 January 2021 27 February 2021 27 January 2021 27 February 2021 27 January 2021 27 February 2021  
Under the current call of energy conservation, emission reduction, and environmental protection, it is of great practical significance to study the cyanide treatment method in the cyanide tailings of gold enterprises [8]. At present, cyanide treatment technologies mainly include electrochemical oxidation, chemical oxidation, adsorption, biological methods, etc. [7; 9; 10; 11; 12]. These methods mainly convert cyanide into non-toxic, harmless, and recyclable substances through chemical or physical reactions, and then the treated harmless tailings and water are recycled to reduce the harm of cyanide to the environment. [PERSON] et al. [10] used electrochemical oxidation to oxidize cyanide in the cyanide tailings pulp to CO\({}_{2}\) and N\({}_{2}\), and the metal cations were reduced and deposited at the cathode. The removal rates of total cyanide (TCN), free cyanide (CN\({}^{-}\)), Cu, and Fe were 80.17%, 84.91%, 84.10%, and 90.91%, respectively. [PERSON] et al. [11] found that the cyanide tailings could meet the backfilling requirements of TSPC after being co-treated with sodium metabasulfite and hydrogen peroxide. The best conditions for the decomposition of cyanide from cyanide tailings are treatment in 0.5 g/L Na\({}_{2}\)S\({}_{2}\)O\({}_{5}\) at pH 10 for 3 h and then 2 mL/L H\({}_{2}\)O\({}_{2}\) is added to the tailings at pH 9 for 4 h. [PERSON] et al. [12] utilized gilsonite to adsorb cyanide in cyanide wastewater; a maximum adsorption of 61.64% was obtained in the size range of \(-1+0.5\) and \(-2+1\) mm of gilsonite. However, these methods have some disadvantages, such as a high consumption of ingredients, harsh operating conditions, difficulty achieving industrial application, no recovery of cyanide in cyanide tailings, and so on. In this study, green treatment of cyanide tailings with the \"filter press backwash-chemical precipitation-gaseous membrane absorption\" method results in the treated cyanide tailings meeting the requirements of TSPC to enter the tailing pond for storage. In this process, a filter press with a reverse washing function is used to realize the harmless treatment of cyanide tailing pulp, the copper element in elution water is recovered by acidification precipitation technology combined with vulcanization precipitation technology, the cyanide in eluent water is recovered by a hollow fiber hydrophobic membrane, and the water after membrane treatment is returned to the pressure filter backwash process as backwash water to realize the recycling of water in the system.