Coke-Based Carbon Sorbent: Results of Gold Extraction in Laboratory and Pilot Tests

Abstract

Coke-based carbon sorbent (CBCS) was produced using special coke fines with the following characteristics: ash, 4.5%; iodine adsorption capacity, 52%; specific surface area, 600 m2 g−1; and total pore volume, 0.4 cm3 g−1. Gold adsorption from real production cyanide solutions in batch and column laboratory experiments was studied. The optimum adsorbent/solution ratio was 0.2 g/20 cm3. Sorption equilibrium occurred after 60 min of phase-time contact. The CBCS maximum adsorption capacity for gold was found to be 1.2 mg g−1. Both the Langmiur and Freundlich isotherm models confirmed that gold adsorption by CBCS proceeds favorably, but the Freundlich isotherm best describes the adsorption equilibrium. The CBCS dynamic exchange capacity (100 g t−1) and full dynamic exchange capacity (4600 g t−1) for gold were determined in column tests. It was revealed using SEM that adsorbate was retained in sorbent pores. The possibility of completely eluting gold from CBCS was demonstrated. A CBCS pilot test to recover gold from 200 dm3 of the cyanide solution containing (mg dm−3) 2.6 Au, 0.42 Ag, and 490 Cu was carried out. The total amount of noble metals (Au + Ag) adsorbed was 99.99% and gold ions was 94%. The CBCS maximum adsorption capacity for gold reached 2900 g t−1.

Influence of Raw Materials and Technological Factors on the Sorption Properties of Blast-Fuel Coke

“…In [26], the authors present the results of positive experience using coke for the adsorption of gold ions from a cyanide solution. Preparation of gold-bearing ore includes crushing, grinding, pelletizing using a pelletizing additive (mainly Portland cement), and sintering.…”

Comparison of the Quality of Gas Equipment at Metallurgical and Coke-Chemical Enterprises and Production Plants

“…The safety rules for metallurgical and coke-chemical enterprises and production plants in the gas sector apply to the designed, those under construction, reconstructed and operating gas facilities of metallurgical and cokechemical enterprises and production plants, to energy facilities associated with the preparation, transportation and consumption of blast furnace, coke, converter, ferroalloy, natural gas, as well as their mixtures with an excess pressure of not more than 1.2 MPa and liquefied hydrocarbon gas with an excess pressure of not more than 1.6 MPa, used as fuel [1]. Design, construction, and reconstruction of gas facilities of metallurgical and coke-chemical enterprises and production plants shall be carried out in accordance with the current building codes and regulations, technological design standards, the requirements of general safety rules for enterprises and organizations of the metallurgical industry, the rules for the construction and safe operation of technological pipelines and other regulations [2][3][4][5][6][7][8][9][10][11][12]. Gas at a metallurgical production plant is distributed through GCPs.…”

Production of Activated Carbon from Sifted Coke and Determination of Its Physicochemical Characteristics

“…With the help of chemical and physical treatment methods, activated carbons with a high specific surface value can be obtained from coals [17]. Carbon sorbents from coke fines can be used to extract gold ions from cyanide solutions, while the degree of gold extraction is 94% [18]. Activation of a fine fraction of sub-bituminous and highly volatile bituminous coal with an alkaline solution leads to the formation of carbon sorbents, which are not inferior to industrial sorbents in static capacity for phenol and chloroform [19].…”