Abstract:Silicon compounds are widely found in uranium ore. Part of silicate mineral reacts with sulfuric acid to form silicic acid in in-situ leaching of uranium by acid. Migration of silicon and its influence on production system in in-situ leaching of uranium by acid method was carried out. The results show that silicic acid enters ion exchange adsorption system with leachate, and more than 99% of it returns to ore bed. Only a very small amount of silicic acid is trapped by adsorption system due to polymerization, part of it is attached to surface of resin, and part of solution flows into extraction system and injection hole. Impact of silicic acid on production system is mainly manifested in three aspects. 1) Silicic acid with a low degree of polymerization will continuously polymerize on surface of ion exchange resin, blocking channel of ion exchange resin, resulting in drop of ion exchange speed and operating capacity. 2) Entry of silicic acid colloid into extraction system will lead to an increase in production of three phases, which can lead to emulsification in severe cases. 3) Silicic acid gel entering borehole will cause borehole to be blocked. In general, massive dissolution of silicon will cause a series of problems such as equipment strain, cost raise, and decrease of production capacity. In order to reduce impact of silicon on production system, sodium hydroxide can be used for resin desiliconization to restore its ion exchange performance, and sodium hydroxide + air compressor can be used to wash well to restore the ability of drilling fluid.