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The utilization of iron sand as a steel-making resource has encountered a new challenge to utilize a by-product of TiO2. Nevertheless, there is no technology that is able to process it economically. Research is being developed towards direct reduction–magnetic separation technology to obtain high grade of titanium slag and easy to process further. In this work, the effect of temperature, and the addition of Na2SO4 on the direct reduction of iron sand, which was followed by the magnetic separation process, was investigated clearly. Before being reduced, the pellets were oxidized at a temperature of 1150°C for 60 minutes. The reduction was carried out in a muffle furnace with temperatures of 1000, 1100, and 1200°C for 120 min with various dosages of Na2SO4 as additives for 0, 3, 6, 9, and 12 wt.%. After that, a wet magnetic separation process was carried out with a 500-gauss magnet to obtain a magnetic concentrate containing metallic iron and non-magnetic tailing containing titanium dioxide. The XRF, XRD, and SEM-EDS analyses were carried out to identify the chemical composition,phase transformation, and morphology of the reduced pellets. The optimum results were obtained at a temperature of 1200°C with an additional dose of 12 wt.% Na2SO4 with metallic iron grade and recovery in concentrate were 89.119% and 94.64%, respectively, while titanium oxide grade and recovery in the tailings were 19.32% and 38.23%, respectively. [ABSTRACT FROM AUTHOR]

One of the Tanggamus gold ore types in Lampung Province is a refractory sulfide dominated by quartz (SiO2) and pyrite (FeS2) minerals with a 10.58% sulfur (S) content. The gold recovery will be less efficient without pretreatment and if only using the conventional method (direct cyanide leaching). An alternative method is introduced by combining physical and chemical routes to gain a preferable gold dissolution rate. This study aimed to determine the effect of pH, temperature, and percent solids on the weight of dissolved gold from various types of leaching feed. First, the gold ore was crushed and ground until the particle size was under 74 microns. Then, the two-stage pretreatment was introduced: the roasting process was conducted to form hematite (F2O3) mineral, which has high magnetic properties with a 1.301% sulfur trace-followed by low wet magnetic separation to separate ore with magnetic and non-magnetic minerals. Next, the gold ore with pretreatment was leached using thiourea solution and iron (III) as an oxidation agent in a 1000 ml reactor, completed with a hotplate-magnetic stirrer and condensing system. The highest gold dissolution was obtained from a magnetic concentrate at pH 1, the temperature of 50°C, thiourea concentration of 0.013 M, iron (III) concentration of 0.0195 M, a solid percentage of 20%, and stirring speed of 600 rpm for 10 hours. This study concluded that gold is more easily dissolved if gold is present in hematite matrices rather than quartz matrices. At low pH, thiourea could be used as an alternative to gold dissolution reagents. [ABSTRACT FROM AUTHOR]

There are two types of iron resources such as primary iron ore and iron sand. In general, primary iron ores use as raw materials in iron and steel making because the iron content is high (± 60%) and can reduce directly. On the other and, iron sand is rarely used as a raw material because the iron content is low (20-40%) but the iron sand reserves are very abundant in Indonesia for instance is about 173 million tons in Kulon Progo, Jogyakarta. In addition, the new regulation of Energy and Mineral Resources Ministry required that iron sands must process before are being export. Therefore, the proper beneficiation methods are need to improve the iron content of iron sand. In this research Kulon Progo iron sand was used as a raw materials because not only the reserves very abundant but also the new iron making plant will build here soon. The combine of ore concentration methods such as tabling and magnetic separation used to improve the iron content. Then, the variable process were inclination of the table (2°,3° and 4°), fraction of feed size (−100 mesh, −150 mesh and −200 mesh) and the magnetic intensity (176, 830, 1500 Gauss). The highest recovery was about 96.75% and the concentrate which is contain 59.78 % Fe achieved by using -200 mesh particle size, 4° inclination of table and 1500 Gauss as a magnetic intensity. In conclusion, this concentrate fulfilled raw material requires of iron making (≥ 55%Fe). [ABSTRACT FROM AUTHOR]