Hadi Purwanto

Carbon doped iron ore using palm kernel shell

This paper pertains to the reduction process of local low grade iron ore using palm kernel shell (PKS). It is well known that low grade iron ores contain high amount of gangue minerals and combined water. Biomass waste (aka agro-residues) from the palm oil industry is an attractive alternative fuel to replace coal as the source of energy in mineral processing, including for the treatment and processing of low grade iron ores. Both iron ore and PKS were mixed with minute addition of distilled water and then fabricated with average spherical diameter of 10-12mm. The green composite pellets were subjected to reduction test using an electric tube furnace. The rate of reduction increased as temperature increases up to 900 °C. The Fe content in the original ore increased almost 12% when 40 mass% of PKS was used. The reduction of 60:40 mass ratios of iron ore to PKS composite pellet produced almost 11.97 mass% of solid carbon which was dispersed uniformly on the surface of iron oxide. The aim of this work is to study carbon deposition of PKS in iron ore through reduction process. Utilization of carbon deposited in low grade iron ore is an interesting method for iron making process as this solid carbon can act as energy source in the reduction process.

Effect of reduction roasting by using bio-char derived from empty fruit bunch on the magnetic properties of Malaysian iron ore

Beneficiation of Malaysian iron ore is becoming necessary as iron resources are depleting. However, the upgrading process is challenging because of the weak magnetic properties of Malaysian iron ore. In this study, bio-char derived from oil palm empty fruit bunch (EFB) was utilized as an energy source for reduction roasting. Mixtures of Malaysian iron ore and the bio-char were pressed into briquettes and subjected to reduction roasting processes at 873–1173 K. The extent of reduction was estimated on the basis of mass loss, and the magnetization of samples was measured using a vibrating sample magnetometer (VSM). When reduced at 873 K, the original goethite-rich ore was converted into hematite. An increase in temperature to 1073 K caused a significant conversion of hematite into magnetite and enhanced the magnetic susceptibility and saturation magnetization of samples. The magnetic properties diminished at 1173 K as the iron ore was partially reduced to wustite. This reduction roasting by using the bio-char can assist in upgrading the iron ore by improving its magnetic properties.

Effect of Numbers of Fringing Electric Field (FEF) Fingers on the Performance of Sensor for Water Content in Soil

The Fringing Electric Field (FEF) element design consideration has been discussed in this paper. This type of sensor is planned to be used for the Non-Destructive Test (NDT)measurement of a moisture level in soil for irrigation system in the field and green house. The effect of soil type and its moisture level has been taken into account by preparing several types of soil moisture level in the lab by performing measurement and calculation as proposed by several papers. It has been shown that the FEF parameters such as the dielectric constant, numbers of finger for FEF design and the working frequency played an important role for FEF design considerations. The performance of the FEF element sensor had been compared with the commercial sensor for benchmarking.

Innovative Process to Enrich Carbon Content of EFB-Derived Biochar as an Alternative Energy Source in Ironmaking

This paper describes the mechanism of a developed process—an integrated pyrolysis-tar decomposition process—to produce oil palm empty fruit bunch- (EFB-) derived biochar with additional solid carbon within the biochar bodies, produced by decomposition of tar vapor on its pore surface, using the chemical vapor infiltration (CVI) method. The product, carbon-infiltrated biochar, was characterized to investigate the possibility to be used as partial coke breeze replacement in ironmaking. Carbon-infiltrated biochar is proposed to be utilized for a sintering process that could reduce the consumption of coke and CO2 emission in iron-steel industry.

Enhancement of oil palm empty fruit bunch char by impregnation of pyrolytic carbon from tar vapor decomposition

This paper describes a technology for condensable vapor from pyrolysis (often referred to as “tar”) of oil palm empty fruit bunch, EFB, to be collected—by EFB char substrate—in the form of pyrolytic carbon to produce a value-added EFB char and to make EFB able to be utilized as a supplementary solid fuel. Chemical vapor infiltration method was employed at atmospheric pressure for tar vapor to undergo secondary decomposition to produce pyrolytic carbon to be deposited within porous char. Porous char in a packed bed was used as the substrate, and impregnated with pyrolytic carbon using tar vapor as a reactant. Char substrate was prepared by slowly heating coarse EFB particles in the packed bed to 400 °C in nitrogen atmosphere. Tar vapor was obtained from fast pyrolysis of fine EFB particles at 400–700 °C, and the weight ratio of fine EFB particles—the tar source—to char substrate was increased from 0.5 to 4.0. The amount of carbon contents of the resultant products by this process was compared to those with...

Development Process For Tar Filtering From Biomass Pyrolysis

This paper presents a new approach for recovering tar produced from the biomass pyrolysis process. Pyrolysis is a promising thermochemical process to utilize biomass to produce gas, char and tar. Tar is a vapour/liquid product containing carbon, and it is often found in producer gas. It needs to be recovered from gas mixture to upgrade its value for the tar to be utilized on its own as a fuel source. In this developed process, steelmaking slag and low-grade iron ore were made porous by the dehydration process, and were then introduced as a tar filter to trap tar produced during biomass pyrolysis. The purpose of this work is to investigate the possibility of using porous materials for tar filtering during the pyrolysis process. Tar vapour infiltrates the porous materials and then decomposes into carbon and gases, where carbon is deposited on the pore surface. Clean gas can be collected and tar can be recovered before being utilized as a renewable energy source by itself. After the trapping process, carbon was found to be deposited within the porous material. The product of the tar filtering will be carbon-deposited material – a potential candidate to be used as a renewable fuel source.

Effect of Sn Addition on Mechanical Properties of Zinc-Based Alloy

Zinc-based alloy is developed as an alternative alloy for giftware material. However, zinc alloy has limitation such as its mechanical properties. Therefore, modifying the properties of zinc based alloy is needed to use it for giftware material. The effect of adding Sn on the mechanical properties and fractography of Zn alloys are investigated. The results indicate that adding 15 wt. % of Sn has significant effect on the improving of tensile strength and elongation of the zinc based alloy due to the formation of AgSn phase. The fracture surface of the tensile test specimen showed a mixed mode of fracture exhibiting ductile failure and brittle failure. Alloy with Sn content up to 15 % tends to have more ductile failure then the brittle one. The alloys of Zn-0.50Ag-15Sn have very good tensile strength and elongation, which are better than Zn-0.50Ag-1Sn and Zn-0.50Ag-7Sn alloys.

Effect of Holding Time on the Corrosion Potential of SS304

Stainless steels suffer from classical sensitization when encounter at certain temperature which results in precipitation of chromium carbide along grain boundary with simultaneous depletion of chromium from near grain boundaries. This study focused on corrosion potential test at different sensitization condition. The degree of chromium carbide precipitation was measured based on thickness of grain boundary. With increasing holding time, the thickness of the chromium depletion zone also increases due to diffusion of chromium into solid solution. Corrosion potential test showed that the heated sample at 700°C for 60 minutes resulted in highest corrosion current density and shifted its corrosion potential to more active potential. The potential tend to increase with increasing the degree of chromium carbide precipitation.

Phase Formation during Reduction of Iron Sand with Soda Ash Flux Addition

Iron sand deposit in Indonesia generally consisted of titanomagnetite with ilmenite lamelaa occurred in magnetite particle structure, therefore direct physical separation through magnetic method at particle size of 400 mesh only capable increasing total iron content up to 60%. In order to increase the grade of iron, decreasing TiO2 content in iron sand was applied by chemical method of alkaline fusion followed by grinding to 100 mesh and magnetic separation. Pre-oxidation was conducted prior to reduction and alkaline flux was added to coal based reduction system of in a rotary kiln. The alkali addition into the reduction system resulted to the formation of metallic iron and non metallic phases, in which sodium titanate compounds as nonmagnetic product can be separated from calcine using separator magnetic. XRD analyses of the concentrate and tailing as magnetic separation products showed concentrate was dominated by metallic phase compared to oxide phase and it doesn’t consisted iron-titan oxide and iron oxide. On the other hand, tailing was consisted iron-titan oxide and iron oxide.