Separation and Recovery of Silver from Silver-manganese Ore with an Environmental Friendly Technique
|Silver manganese Silver manganese separation Iron filing Reducing leaching Dynamics Gravity desliming Thiourea
Since the end of the last century of Hunan, Hubei, Anhui, Jiangxi, Hebei, Inner Mongolia, Guangxi, have found a number of silver-containing manganese deposit, these deposits manganese content of between 10% to 30%, low grade silver at 150 g / t high up to 1000 g / t. Silver manganese ore in China is an important ore of silver, but because Xuanye technical problems, has not yet been effective development and utilization of such ore. In this paper, the research and progress at home and abroad on the silver manganese processing. Traditional process based on thermodynamic analysis and exploratory comparative test the iron filings restore acid leaching - gravity desliming - new technology of thiourea leaching silver. New technology to achieve a silver manganese clean leaching, is an environment-friendly wet leaching method, is also a different grade manganese silicon the complex oxide ore processing technology innovation. Sucrose restore dip manganese, hydrogen peroxide reduction Baptist manganese and iron reduction Baptist manganese exploratory comparative trials, reducing reagent, the amount of acid, the ratio of liquid to solid silver manganese particle size, reaction temperature were analyzed by single factor experiment and The reaction time of manganese leaching rate, and explore the the three restore Baptist manganese process of single factor test conditions under optimum leaching conditions. Trials comparing, and integrated the actual situation, this study ultimately chose the iron filings restore Baptist manganese from silver-manganese separation test. Provide a theoretical basis for the feasibility of thermodynamic calculations for the the iron filings Baptist manganese process, calculate the standard Gibbs free energy of the leaching reaction process is the equilibrium constant of the reaction, positive reaction from the thermodynamic theory very thorough . Iron and experimental research and mechanism of reductive leaching silver manganese analysis. The dynamics test studies have shown that manganese leaching rate of ore particle size, the impact of acid mine ratio and iron ore than iron filings restore leach silver manganese reaction controlled by diffusion and export incomplete kinetic equation: Through thermodynamics, kinetics studies to determine the process required roughly orthogonal design needed to confirm the optimum conditions. Iron filings reductive leaching manganese optimum conditions for the silver manganese ore particle size of 0.088 mm to 0.074 mm, acid mine than 0.6:1, iron ore ratio of 1:12, liquid to solid ratio of 3:1, leaching time of 45 min and leaching temperature room temperature, the manganese leaching rate up to 96.67%, while silver dip manganese slag recovery was 95.48%, silver manganese separation, and provide the necessary conditions for the follow-up process. Reducing leaching and separation of silver manganese ore of iron filings dip manganese slag gravity desliming - Thiourea silver - zinc replacement process. Gravity desliming spiral chute on leaching manganese slag, of manganese slag leaching of silver grade of 473.23 g / t to 1113.10 g / t, silver recovery rate of 98.32%; thiourea leaching silver method for the optimum leaching conditions liquid-solid ratio 12:1, thiourea concentration of 12 g / L, Fe3 0.012 mol / L, pH 1.5 to 2.0, temperature 40 ° C ~~ 60 ℃, leaching time 120 min, this time silver leaching rate of 96.54%; The optimum conditions for zinc replacement silver process: zinc powder added to the amount of 2 g / L, the replacement time of 15 min, stirring speed of 180 r / min, the silver conversion rate of 97.73%. The iron filings restore the acid leaching - gravity desliming - new technology of thiourea leaching silver ultimate silver recovery of 88.57%, with a reducing agent is easy to get, and low running costs, is an efficient and environment-friendly new technology.