Study on well spacing in in-situ leaching mining based on the tubular leaching experiment

In order to investigate the reasonable well spacing for in-situ leaching, the acid tubular leaching experiment is carried out on uranium ore samples from I-II cycles of a deposit in Xinjiang.The experiment is divided into two stages:saturated water leaching, reagent free leaching and dilute acid leaching with 5 g/L sulfuric acid.In the experiment, five monitoring sections are arranged from the injection end to the outlet end at a certain interval, and samples are taken at 8 h intervals.The parameters of uranium concentration, pH value, ferric ion and total iron concentration of the samples are analyzed to explore the variation characteristics of parameters in different monitoring sections and their relationship with the leaching agent migration distance.The results show that the process of in-situ leaching is a gradual accumulation of uranium, and the accumulation rate is controlled by well spacing; the peak value of uranium concentration is positively related to the concentration of leaching agent and the grade of uranium ore; the speed of the peak value of uranium concentration is directly proportional to the infiltration rate; according to the fitting formula, the peak uranium concentration does not increase linearly with the increase of leaching path, but has a logarithmic relationship with the migration distance of leaching agent.It increases with the extension of leaching path, but the growth rate gradually slows down.In the 40 m leaching process, 95% of the accumulation of uranium concentration is completed in the first 27 m.Therefore, the reasonable well spacing of acid in-situ leaching mining is about 27 m.