Fajar Nurjaman

Coke and coal as reductants in manganese ore smelting: An experiment

Abstract The effect of coke and bituminous coal on the reduction of medium-grade manganese ore in ferromanganese production was investigated. Charges of 30 kg medium grade manganese ore, 12 kg limestone and varied amounts of coke and coal were smelted in a Submerged Electric Arc Furnace (SAF) at temperatures of 1300°C to 1500°C. The composition of the ferromanganese and the slag were determined by X-Ray Fluorescence. It was found that using coke as a single reductant resulted in a 96% yield of ferromanganese which was higher than by using coal either as a single reductant or in a mixture of coal and coke. It was also found that using coke as a single reductant resulted in the lowest specific energy consumption. Using coal as reductant produced ferromanganese containing high sulfur and phosphorus.

Effect of slag basicity in ferromanganese production using medium-grade manganese ore from East Java-Indonesia

ABSTRACT Ferromanganese is one of the most important alloying elements in steel industries. In this work, the production of ferromanganese was carried out using three-phase submerged mini electric arc furnace. The effect of slag basicity due to the addition of a various amount of limestone as fluxing agent on this smelting process was investigated. The chemical composition of ferromanganese and slag was analysed with X-ray fluorescence. From this experiment, the optimum slag basicity was 0.8 that produced 8.2 kg of ferromanganese with 78.1% Mn, 12.7% Fe, and 8.9% Si. It resulted from 30 kg of manganese ore, 7.5 kg of cokes, and 12 kg of limestone.

Ferromanganese production from the mixture of medium-grade and low-grade Indonesian manganese ore

Abstract In this present work, the ferromanganese was produced by mixing two different grades of Indonesian manganese ore. The possibility of mixing medium-grade manganese ore (27.77 Mn–4.44 Fe–14.7 Si) and low-grade manganese ore (16.39 Mn–19.22 Fe–20.23 Si) to produce ferromanganese was investigated clearly. The 30 Kg of manganese ore mixture was smelting by using sub-merged arc furnace (SAF). The composition of manganese ore mixture in percent weight to produce ferromanganese was 100–0, 75–25, 50–50, 25–75, and 0–100 for medium-grade and low-grade manganese ore, respectively. These ores were smelted together with stoichiometry cokes. Limestone was added in this smelting process to obtain 0.75 of basicity in this smelting process. The chemical composition of ferromanganese was analyzed with X-Ray Fluorescence (XRF). From the smelting process, the ferromanganese with 31.13 Mn–59.84 Fe–7.84 Si and 75.19 Mn–20.17 Fe–3.27 Si were resulted from 100% of low-grade and medium-grade manganese ore, respectively. The Mn-content in ferromanganese and the yield of ferromanganese production were decreased with the increasing of low-grade manganese ore in the mixture of low-grade and medium-grade manganese ore smelting process.

Optimization of Tin Magneto Electrodeposition under Additive Electrolyte Influence Using Taguchi Method Application

Operational conditions of tin magneto electrodeposition were successfully obtained using Taguchi technique. The parameters which optimize using Taguchi orthogonal array were tin sulphate, sulphuric acid, gluconate concentrations and magnetic strength (Tesla). The gluconate in this process is additive electrolyte which acts as an inhibitor against corrosion. The effects of those parameters toward the fractal dimension of tin electrodeposits were studied in this research. The results show that microstructures of tin electrodeposit from magneto electrodeposition have a compact structure than the tin electrodeposits of conventional electrodeposition.

Application of Taguchi Optimization on the Cassava Starch Wastewater Electrocoagulation Using a Bipolar Stainless Steel Electrode in the Presence Additive Electrolyte

Optimization of tapioca wastewater treatment by electrocoagulation has been conducted. Taguchi design experiment was used to calculate the optimum condition. Electrode distance, an electrical resistance of the wastewater and time of operation were used as the parameters. The results show that the electrocoagulation using bipolar stainless steel electrode was able to treat the cassava starch wastewater. The maximum pollutant removal percentage was achieved by the electrical resistance of 60 ohms at 1.5 cm electrode distance for 30 minutes.