SEPARATION OF WARINGIN HEAVY MINERAL SANDS FROM CENTRAL KALIMANTAN

Central Kalimantan has grown rapidly as a heavy mineral producer. Zircon is the main mineral concentrate, but other valuable heavy minerals are present. With particular interest in the upgrading of zircon and its recovery, tekMIRA’s laboratory has developed benefi ciation steps of heavy minerals to produce marketable zircon con- centrate. Using a series of concentration equipments that includes spiral concentrator, shaking table, magnetic separator and electrostatic separator; the content of zircon in the end concentrate reaches up to 65% ZrO2

MAGNETIZING ROASTING OF IRON LATERITE ORE BY SUB-BITUMINOUS COAL AS REDUCTANT

The overburden of Pomalaa’s laterite ore is characterized by its high content of iron with average Fe content of 41.8 % and can be classified as iron cap deposit. As a significant iron ore resource to be used as raw material for iron and steel industry, upgrading of laterite ore is necessary to meet the requirement for iron making. The ore was treated by magnetized roasting technique followed by mag- netic separation to produce high iron content of magnetic concentrate. The ore were dominated by limonite iron minerals and has low magnetic property. However, roasting reduction treatment increased the magnetic properties of the ore due to transformation of magnetite

STRUCTURAL CHANGES OF POMALAA LATERITIC ORE DUE TO COAL-BASED MAGNETIZING ROASTING

Overburden of Indonesia’s laterite ore at Pomalaa is considered as an iron cap. It performs low iron grade (41.88%) and high silica and aluminum oxide contents (18.47% and 9.46%, respectively). Around 54.74% of size distribution belong to -325 mesh fraction. Limonite iron mineral dominates in the ore in the range of 80-90% with water content of about 40%. Proven deposits of laterite iron ore are about  222 million tons. As a significant resources iron ore to be used as raw material for iron and steel industries, the iron content must be upgraded to meet the requirement of iron making industry. Magnetizing roasting technique can be conducted to change the paramagnetic iron mineral (such as hema- tite, goethite, limonite or siderite) into magnetite one that has high magnetic intensity. Therefore, the changed iron mineral can be concentrated using low-intensity, magnetic separator. Coal, mixed in ore composite may also enhance the development of coal-based magnetizing roasting processes in order to reach the desired temperature. Recently, reduced iron products from many different processes have been used as the main feed mixed with steel scrap. On the other hand, iron ore resources is getting dominated by low grade lateritic iron ore with specific content of water crystal. The abundant deposits of low grade lateritic iron ore and low rank coal in Indonesia can be used as suitable resources for raw materials in the iron and steel- making industry. Iron structural changes during magnetizing roasting process using coal as reductant agent was observed. The result showed that the non-magnetic limonite ore has been changed in to metallic iron and the iron recovery in the magnetic product depended on the coal ratio in the pellet composite. The magnetic product can be used for the development of lateritic iron ore as one of the alternatives to metallized iron feed for iron making industry

REDUCTION OF GOETHITIC IRON ORE USING THERMOGRAVIMETRIC METHOD

Compared to main iron ore minerals, either hematite or magnetite, Indonesian goethite is relatively abundant. However, this is not common to be used as feed material in iron making industries. Limitation in Indonesian high quality iron ore resources, the iron making industries have to seek another iron source such as the low grade iron ore of goethitic ore. Evaluation using thermogravimetric method was employed for analyzing behavior of goethitic composite pellet during reduction. The data show that reduction of goethitic iron ore is started by transforming goethite to hematite and then followed by iron reduction. The reduction was started by Fe3O4 formation at 442 °C and Fe at 910 °C. At those temperatures the composite pellet lost its weight. Identifying the FeO is hardly difficult due to the short range of phase existence

PEMBUATAN ZIRKONIA SEMI STABIL DARI PASIR ZIRKON KALIMANTAN TENGAH DENGAN MENGGUNAKAN BAHAN PENSTABIL CAMPURAN CaO DAN MgO

Pembuatan zirkonia semi stabil (PSZ) dari pasir zirkon Kalimantan Tengah telah dilakukan dengan metode disosiasi termal pada skala laboratorium. Pasir zirkon Kalimantan Tengah yang digunakan mempunyai kadar 58,95% ZrO2 dengan pengotor terbanyak SiO2 28,21%, Fe2O3 1,30%, dan TiO2 6,68%. Kadar zirkon sebesar ini belum ekonomis apabila digunakan untuk pembuatan zirkonia semi stabil, oleh karena itu perlu dilakukan peningkatan kadar sehingga mencapai kadar >65% ZrO2. Peningkatan kadar pasir zirkon dilakukan melalui pemisahan mineral pengotornya dengan menggunakan kombinasi serangkaian peralatan yang terdiri dari meja goyang, pemisah magnetik, dan high tension separator (HTS). Dari hasil percobaan peningkatan kadar diperoleh konsentrat pasir zirkon berkadar 66,15% ZrO2, dengan perolehan sebesar 88,95%. Untuk memperoleh zirkonia semi stabil, bahan penstabil berupa campuran CaO dengan MgO ditambahkan ke dalam zirkonia berkadar 93,81% yang dibuat dari pasir zirkon dengan cara mixing dan sintering. Untuk mendapatkan kondisi pembuatan zirkonia semi stabil (PSZ) yang baik, perlu dilakukan percobaan dengan memvariasikan suhu sintering dan jumlah bahan penstabil. Kemudian produk yang diproleh dianalisis kadar ZrO2nya dan diuji bentuk struktur kristalnya dengan difraksi sinar-x. Hasil difraksi sinar-x terhadap zirkonia semi stabil (PSZ) yang diperoleh menunjukkan hanya puncak ZrO2 dengan bentuk struktur kristal tetragonal terjadi pada suhu sintering 1100oC dengan jumlah bahan penstabil 11% mol (5%berat) CaO dan 11% mol (3,6%berat) MgO

APPLICATION OF REVERSE FLOTATION METHOD FOR THE UPGRADING OF IRON OXIDE CONTAINED IN CALCINE LATERITE ORE

Reverse flotation was adopted for Indonesian iron-rich laterite ore from Pomalaa to float siliceous minerals in the separation of iron mineral. Nickel siliceous mineral such as garnierite is one of the silicate minerals containing in laterite ore that are undesirable and must be eliminated from the ore before used as raw material for iron making industry. Calcine laterite product was obtained from reduction process in rotary kiln for 3 hours at 900 °C by transforming limonite/goethite to magnetite containing Fe 45.6 % and Ni 1.16 %. The reverse flotation tests were focused on the separation of iron mineral from nickel mineral using amine complex, ARMAC-C, a commercially available amine thioacetate as collector. Influences of pulp pH, dosages of collector amine complex and frother, and also solid percent of pulp on the reverse flotation of calcine laterite ore were investigated. The optimal condition was obtained at pH 10, collector 1000 g/t and frother 25 g/t at solid percent of 30%. The test results show that after one-stage rough reverse flotation the concentrate had Fe and Ni grades of 77.5% and 0.5% with recoveries of 57.3% and 33.7%, respectively. Therefore, it is possible to use iron-rich lateritic ore to produce magnetic concentrates by using magnetizing roasting followed by reverse iron flotation

THE CURRENT STATUS OF IRON MINERALS IN INDONESIA

Indonesia has great iron mineral resources, comprising primary iron ore (17 %), iron sand (8 %) and lateritic iron ore (75 %). Nowadays, Indonesia’s primary iron (hematite, magnetite) has not been em- powered yet, due to the scattered area of the resources location. Meanwhile, national iron sand is commonly used for cement industries and its potency has not supported national steel industries yet because of low iron content (45-48 %). However there is an opportunity to be processed by using Ausmelt process technology. At present, lateritic iron ore is being used as coal liquefaction catalyst in the form of limonite, but hydrometallurgy would be a promising solution to beneficiate lateritic iron ore for steel industries

TIN-BASED ALLOY FOR FUEL CATALYST

Tin-based fuel catalyst, if dipped into a gasoline-containing tank will increase fuel efficiency. The catalyst has been used since 60 years ago. Its usage will save the fuel and increase the use of tin as expected by tin-producers. Though the mechanism of catalytic reaction has not been clearly understood, several research regarding catalyst performance have been conducted. Moreover some companies have already produced such a catalyst. The tin alloy catalyst was made by melting tin and other metals at specific compositions in a burner and casted into dif- ferent shapes. In term of evaluating the contact between the fuel and the catalyst as well as assessing the alloy catalytic mechanism, the samples were dipped in gasoline and stirred for 3 days. The gasoline with and without catalyst were analyzed using infrared and showed that the spectra appeared at 875, 835, 538, 343 and 229 cm-1 after 3-day dipped. The peaks resulted for catalytic interaction between Sn and gasoline. Fuel efficiency was measured through static and dynamic tests. The former was conducted using a genset and lawn mower by running the diesel-containing engines in empty load condition. The result showed that efficiency of catalyst-containing diesel consumption was still low, ranged between 0.6 - 5%. Other static tests were performed at LEMIGAS using Toyota and Isuzu car engines. Using gasoline and diesel respectively. Effect of catalyst on the car with gasoline improves engine capacity to 8.79%, and increases fuel consumption to 1.03%. The catalyst applied the car with diesel enhances the capacity to 11.38 % and increases fuel consumption to 9.39%. Dynamic tests conducted to motor bikes and cars show the efficiency of fuel consumption around 5-17.5%. It means that tin-alloys based catalyst for efficiency of fuel use is prospective. Such a catalyst is easy to be made and utilized