STUDY THE EFFECT OF NICKEL LATERITE ORE COMPOSITION ON THE NICKEL LEACHING PERFORMANCE IN SULFURIC ACID SOLUTION AT ATMOSPHERIC PRESSURE

• Main Author: CHANDRA - Nim: 12514044 , MICHAEL
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/28895
• Institution: Institut Teknologi Bandung

<p align="justify">Performance of nickel leaching from laterite ore is dependent on chemical composition, particle size and mineralogy of the ore as well as leaching parameters which include concentration of leaching agent, leaching temperature, time and slurry density. Chemical composition of the ore which determines the performance of leaching is the content of nickel, iron and magnesium. During atmospheric agitation leaching of limonite ore, dissolved iron is not precipitated during leaching; therefore, the higher iron content in ore the higher acid consumption, too. Although limonite ore has magnesium content which is low in comparison to the content of magnesium in saprolite ore, the higher magnesium content in the ore would also enhance the acid consumption. In this research, the effect of variation of Fe and Mg content in limonite ore on the atmospheric leaching performance, namely nickel extraction, dissolved iron and sulfuric acid consumption. <br /> <br /> <br /> The ore samples which has different Fe and Mg content were originally from Tanjung Buli Halmahera, Tapunopaka South East Sulawesi and Mandiodo South East Sulawesi which were sent by PT. Antam. In addition, two more ore sample prepared by blending were also used. Series of leaching experiments by using limonite ores with different iron and magnesium content in sulfuric acid solution at atmospheric pressure were carried out to study the effect of the contents of Fe and Mg in ore on nickel and iron extractions as well as acid consumption. Variation of the amount of added acid in kg/ton-ore was also made. The leaching experiments were done for 24 hours in which solution sampling was made periodically every 15, 30, 60, 120, 240, 480, 720, dan 1440 minutes after the start of the leaching. Measurements of concentrations of dissolved nickel, iron, and magnesium were performed by using Atomic Absorption Spectrophotometer (AAS) to determine extraction percentage of these metals. Constant variables for the leaching experiments are temperature which was maintained at 95oC, ore size fraction of -65+100# (149-208 µm) and solid percentage of 15%. <p align="justify"> <br /> <br /> <br /> The experimental results show an increase in magnesium content and decrease in iron content tends to increasing the nickel extraction. Meanwhile for acid consumption, variations of magnesium and iron content show variety of acid consumption. The best leaching conditions which give the highest nickel extraction obtained at 2M sulfuric acid. In this condition, nickel extraction obtained after 24 hour of leaching is 98.13% with acid consumption of 1156.29 kg H2SO4/ton ores. Regression equation obtained for acid consumption &#119910; = 1,027 %&#119872;&#119892;&#119874; + 11,128 %&#119865;&#119890; + 831,174 and for nickel extraction &#119911; = 0,758 %&#119872;&#119892;&#119874; + 0,252 %&#119865;&#119890; + 81,567 on the best leaching condition. <br />