The most important aspects of heap leaching is it"s potential to produce uranium at lower costs, if it is applied to a suitable ore deposit. Prior to set up a heap at industrial scale, it is necessary to collect data on leaching behavior of the ore by laboratory column leaching tests. This paper discusses the research work performed to determine permeability of the ore,the consumption of chemicals, the composition of leach solution and influence of effective parameters on uranium recovery. A laboratory system was developed for simultaneous column leaching test on 6 column with 6 different samples coming from different points of ore body at the same time.Tests were carried out on 3 samples (2 column of each), 1. Main ore body 2. Representative sample from ores 3. Radiometric concentrate of surface sample Dependence of the recovery with the treatment condition, time (d), L/S (l/t), acid(kg/t) oxidant (kg/t), PH, EMF were studied. As a result the recovery of U was more than 90% for a period of 3 weeks and (98% in 4 weeks) while the consumption of acid was 55kg/t.

A mathematical model is described which has been developed to analyse flow through a restructured soil during leaching with the Horizontal Leaching Technique. This new technique has been developed through field work in Turkey and Jamaica. The proposed model was based on field data compiled in Jamaica and it reveals that leaching will be much more effective in the upper more permeable horizons of the soil than it will be in the less permeable deeper layers. The model indicates that management of ponding on the surface of. the field can be achieved by controlling the rate of water application. Increasing the distance to the installed drainage system will increase the amount of salt that has to be leached and also reduce the rate of flow through the soil to the drain.

Improvement of saline soils is very important from the point of view of soil and water resources conservation. Excess Solution salts in the root zone can reduce water uptake by the plant due to reduced soil osmotic potential. Necessary strategy in dealing with this issue is reducing the soil salinity to optimum level by capital leaching. The purpose of this study was to investigate the application of different amounts of leaching water in reducing salinity and evaluating experimental and theoretical models in predicting final salinity. This research was carried out in a part of Mohammadabad lands of Sistan plain as a randomized complete block. This experiment are carried out with five treatments and four iterations using test plots with one-to-one meter. Leaching was performed using 100 cm of water in four intervals of 25 cm. The required physical and chemical analyses before and after leaching and after the application of each irrigation cycle in treatments and at different depths up to 100 cm of soil were performed on the collected data. The results showed that the use of 100 cm of water for leaching could reduce the soil salinity class from S2A2 to S1A2. Experimental and theoretical models were evaluated and the results showed that theoretical models predicted the final salinity better than experimental models. Of all the experimental and theoretical models studied in this study, the theoretical model of a single reservoir with a correlation coefficient of 94% had the best results.

An experimental study was conducted to determine the effects of the leaching parameters on impurity ion concentrations of the liquid phase in ulexite leaching. Powdered ulexite ore was leached in an aqueous medium with sulfur dioxide. The Taguchi experimental design approach and statistical methods were used to evaluate the effects of the leaching parameters (solid/liquid ratio, temperature, pH, particle size, time) on impurity ion concentrations (concentrations of magnesium, calcium, iron ions) in the liquid phase. The average B2O3 leaching ratio of ulexite ore was found as 98. 56 % (± 0. 95). Statistically effective leaching parameters on impurity concentrations (and delta values for concentrations) were found as pH (770 ppm) for magnesium, solid/liquid ratio (372 ppm) for calcium ion concentrations. The examined parameters were not found effective for iron ion concentrations.

The leaching kinetics of smithsonite ore in acetic acid solutions, an environmental friend, and natural reagent was investigated. The influence of parameters such as reaction temperature, particle size, solid-liquid ratio and acid concentration was studied in order to reveal the leaching kinetics of smithsonite ore. In this study, experimental and statistical methods were carried out in order to analyze the kinetics data to investigate a kinetics model which describes the dissolution. The results indicate that the unreacted shrinking core model for fluid-solid heterogeneous reactions was favorable for the leaching process. The apparent activation energy of the leaching process was found as 74 kJ/ mol. It was determined that the leaching rate of smithsonite was controlled by the chemical reaction below: (1-x)1/3=3.7×105e-74/RTt.

The reclamation of saline‐ sodic soils is an important issue in agriculture and agronomy programs. In arid and semiarid areas, rainfall is not sufficient for leaching of salts from root zone and excess of soluble salts in the soil root zone can reduce water uptake of the plant. This is due to the decrease in the osmotic potential of soil solution and also degradation of soil structure because of sodium which could be toxic to the plant. In this field study reclamation of saline‐sodic soils at four stations in Minab, south of Iran was investigated. The experimental design of the study was double‐ring. The leaching was investigated up to 100 cm depth of soil. As the leaching process continued, soluble salts were washed away from soils profile of the agronomy programs and the salinity of the soil surface layer were reduced to a level suitable for cultivation of salt tolerant and semitolerant plants.