Study On The Chemical Jamming Mechanism Of In-situ Leaching Process In Ledge Of Bayan Ula Uranium Ore Deposit

Bayan Ula uranium deposit is the first developed uranium ore bed in Erlian basin of Inner Mongolia,and is the other uranium mine which is also used to acid in-situ leaching after Yili basin of Xinjiang.Although,the ore grade of uranium is low and thickness of ore bed is big in the deposit,permeability of deposit is great.It is is helpful for in-situ leaching mining.So the deposit has a good development prospect.With the operation of the production system,pressure of flow is increasing in injected well.It means that has problem of chemical clogging in ore-bearing bed.On the basis of analyzing the mineral characteristics of ore-bearing bed,chemical clogging of ledge is studied in this paper.Lixivium-mineral balance is simulated according to the leaching liquid ingredients,with the model of geochemical program(PHREEQC).And the mineral types of blocking is determined.Reason and conditions of chemical clogging is analyzed in the deposit.Model is established to simulate the process of leaching liquid-mineral interaction with ionic concentration of leaching solution and Lixivium.Amount and volume of blocking is calculated by the model.And flow of injection is compared with the decline of porosity.On the basis of these Analysis,the mechanism of chemical jamming is revealed in Bayan Ula deposit.The results show that,content of pyrite and calcium carbonate is relatively high.Strongly acidic leaching liquid of high salinity could dissolve these mineral when the solution is injected in ore-bearing bed.It increases the concentration of Ca2+ and Fe3+ in the solution,especially under the condition of oxidation.When concentration of Ca2+ and Fe3+ over value of equilibrium concentration boundary,namely the reaction condition index of concentration greater than zero,precipitation of gypsum and iron mineral is emerged.The mineral could fill pore of ore-bearing.It decreases porosity,results in the decrease of permeability,increase pressure of injection and causes of the chemical clogging in ore-bearing bed.The simulation results in conformity with the deposit practical congestion.It is considered that the balance simulated discussion of chemical jamming mechanism combined with simulation of leaching liquid-mineral interaction in ore-bearing bed is effective and feasible.