Generation of sodium cyanide by coal gasification for gold recovery factories

The aim was to assess the technological feasibility of generating sodium cyanide by coal gasification, study effects process parameters (temperature, experiment duration, type) on concentration in resulting solutions, as well identify optimal modes process. Experiments were carried out a laboratory setup consisting tubular cylindrical furnace equipped with working compartment form corundum tube. Lignite and charcoal, preliminarily crushed increase specific surface area, investigated. A solution produced sorption gaseous hydrocyanic acid (a syngas component) carbonate solution. NaOH (pH = 10) installed an ice bath used system absorbers. content determined titrimetric method. HSC Chemistry 5.1 software package for thermodynamic calculations. During gasification charcoal temperature range 600–800oC, solutions 0.03–0.08 wt% obtained. An from 600 900oC led 4-fold decrease alkaline solution, under same duration experiments. regression equation derived dependence NaCN It shown that generation conditions yields concentrations comparable those gold cyanidation at recovery plants. installation lines directly production areas plants will reduce costs eliminating expenses purchasing, transporting storing reagents.