Processing of Metasomatite Deposit of Saghand Anomaly No. 5 by Sulphuric Acid Digestion

This paper deals with the study of digestion processes effectiveness in processing metasomatite deposit of the Saghand anomaly No.5. To accomplish the task, the samples from metasomatite rocks of the Saghand anomaly No.5 were studied in laboratory. The sample containing minerals such as calcite, quartz, albite, actinolite, ilmenite, rutil, chevkenide, bastnasite, monazite, and sphen were first concentrated using the method of pre-concentration (electrostatic, magnetic and gravitation) which led to an increase in the rate of their heavy mineral from 10% to 50%. The purpose was to eliminate or reduce, calcite and other obtrusive minerals, and consequently have a better dissolution and a less consumption of acid. At this stage of study, and by using the produced concentrate, the effectiveness of the digesting process, the effect of different parameters such as temperature, digestion time, sulfuric acid concentration, solid-to-liquid ratio and oxidant concentration, with the aim of determining their optimum values, were studied which resulted in the following values for the above-mentioned parameters: temperature: 200°C, digestion time: 2h, sulfuric acid concentration: 10.8M, solid-to-liquid ratio: 0.33 (w/v), and oxidant (nitric acide) concentration: 5.3M. Under these conditions, the recovery extents of uranium, thorium and REE were found to be 85%, 83%, and 42%, respectively.