Process for leaching rare earth from ion-adsorption type rare earth ore without using ammonium salt

Abstract

The invention relates to a process for leaching rare earth from ion-adsorption type rare earth ore without using ammonium salt. The process comprises the step of replacing ammonium salt by taking a mixture of calcium, magnesium and sodium salts as a leaching agent and taking non-ammonium salts, such as calcium hydroxide, magnesium hydrate or sodium hydroxide as a precipitator. According to the process disclosed by the invention, the ammonia nitrogen pollution problem in exploitation of ion-adsorption type rare earth is radically solved; environmental-friendly exploitation of the ion-adsorption type rare earth can be realized; the process disclosed by the invention has higher economic benefit and social benefit.

Description

technical field [0001] The invention relates to a process for leaching rare earths from non-ammonium salts of ion-adsorption rare earth ores. Background technique [0002] The mining of ion-adsorption rare earth mines in my country has a history of several decades. At the beginning of mining, the pool leaching process of sodium chloride was used as the leaching agent. Later, because sodium chloride would make the soil salinized, it was changed to ammonium sulfate. The leaching agent forms a mining process for ion-absorbing rare earths with ammonium sulfate as the leaching agent and ammonium bicarbonate as the precipitating agent, and gradually develops from the pool leaching process to an in-situ leaching process that protects the ecology. However, for a long time, the process of using ammonium sulfate as the leaching agent and ammonium bicarbonate as the precipitating agent has lost a large amount of ammonium ions no matter during mining or in the ore body after mining rare ...

AI Technical Summary

Problems solved by technology

However, for a long time, the process of using ammonium sulfate as the leaching agent and ammonium bicarbonate as the precipitating agent has lost a large amount of ammonium ions no matter in the mine mining or in the ore body after the rare earth mining, causing the surrounding environment of the mine to be polluted and the water body to be polluted. Ammonia nitrogen seriously exceeds the standard (ammonia nitrogen content in mining wastewater is 100-400mg / L), so far it cannot be treated up to the standard, leaving long-term environmental pollution problems