Possible heat effects during chemical decomposition and geotechnological leaching of sulfide ores and intermediate products

Abstract

1. Thermodynamic calculations show that the interactions of most of the minerals considered in this review with sulfuric acid, should result in a significant heat release, which in the first instance is related to the oxidation of the sulfides. 2. The lower the Me/S ratio in the sulfide, the greater the heat effect from the oxidation of 1 g of sulfide. At the same time, calculations of the equivalent unit show that for certain exceptions (covellite) the value of ΔQ (kcal/g·at·S) is approximately constant at 215±17 kcal. 3. The main component of the heat effect in the reaction of waste slag with sulfuric acid is determined (from experimental results) by the reaction of the nickel-containing minerals; with refractory copper minerals, primarily by the oxidation of the iron-containing sulfides (faster than pyrrhotite) and partly by the oxidation of the nickel-containing components. Sulfides of copper in this case are virtually undissolved. 4. On the previous assumptions, the provisional temperature effect of the process, based on the experimental data, can raise the temperature of slag and copper ores up to 100°C and 480°C respectively.