Pengaruh Penambahan Oksidatoor Pada Proses Pelindian Oksidatif Konsentrat Galena

Kebutuhan logam timbal di dalam negeri saat ini masih cukup besar, namun tidak diimbangi dengan kemampuan industri pemurnian timbal domestik. Sumber daya bijih timbal yang tersedia di Indonesia cukup besar sehingga memberikan peluang untuk pembangunan proses pengolahan timbal. Proses pemurnian timbal baik dari sumber mineral maupun daur ulang dari komponen aki bekas hingga saat ini umumnya menggunakan jalur pirometalurgi yang memberikan dampak buruk pada lingkungan, sehingga jalur hidro-elektro metalurgi menjadi solusi. Penelitian ini mencakup pemurnian timbal melalui proses hidrometalurgi dengan melakukan pelindian oksidatif konsentrat galena dalam media asam flosilikat dengan menggunakan oksidator berupa hidrogen peroksida dan timbal oksida (PbO2) dari katoda aki bekas. Penentuan parameter operasi pelindian seperti fraksi ukuran partikel konsentrat galena, jumlah penambahan oksidator PbO2 dari katoda aki bekas, kecepatan agitasi, temperatur pelindian, dan persentase padatan operasi pelindian dilakukan untuk menekan konsumsi reagen sehingga dicapai proses pelindian yang efisien. Pada penelitian ini dilakukan proses pelindian dengan memvariasikan penambahan Oksidator PbO2 dari katoda aki bekas sedangkan parameter lain pada kondisi konstan. Hasil pelindian menunjukkan bahwa persen ekstraksi timbal tertinggi diperoleh dengan melakukan pelindian pada penambahan oksidator PbO2 sebanyak 1,5 kali basis stoikiometri

Pengaruh Penambahan Oksidatoor pada Proses Pelindian Oksidatif Konsentrat Galena

Kebutuhan logam timbal di dalam negeri saat ini masih cukup besar, namun tidak diimbangi dengan kemampuan industri pemurnian timbal domestik. Sumber daya bijih timbal yang tersedia di Indonesia cukup besar sehingga memberikan peluang untuk pembangunan proses pengolahan timbal. Proses pemurnian timbal baik dari sumber mineral maupun daur ulang dari komponen aki bekas hingga saat ini umumnya menggunakan jalur pirometalurgi yang memberikan dampak buruk pada lingkungan, sehingga jalur hidro-elektro metalurgi menjadi solusi. Penelitian ini mencakup pemurnian timbal melalui proses hidrometalurgi dengan melakukan pelindian oksidatif konsentrat galena dalam media asam flosilikat dengan menggunakan oksidator berupa hidrogen peroksida dan timbal oksida (PbO2) dari katoda aki bekas. Penentuan parameter operasi pelindian seperti fraksi ukuran partikel konsentrat galena, jumlah penambahan oksidator PbO2 dari katoda aki bekas, kecepatan agitasi, temperatur pelindian, dan persentase padatan operasi pelindian dilakukan untuk menekan konsumsi reagen sehingga dicapai proses pelindian yang efisien. Pada penelitian ini dilakukan proses pelindian dengan memvariasikan penambahan Oksidator PbO2 dari katoda aki bekas sedangkan parameter lain pada kondisi konstan. Hasil pelindian menunjukkan bahwa persen ekstraksi timbal tertinggi diperoleh dengan melakukan pelindian pada penambahan oksidator PbO2 sebanyak 1,5 kali basis stoikiometri

Design of Rolling Machine to Improve Mechanical Properties of Strapping-band Steel and Low Carbon Steel type SHP 440

The modification of new roll machine should be able to produce very good mechanical and physical properties of different metal materials. Furthermore, this also can affect the     microstructure of the metal. Conventional low carbon steel with a ferrite-perlite microstructure has relatively low mechanical properties. Due to it our research work refers to the mechanism of metal strengthening by means of grain refinement with the assumption that it will increase the strength and toughness of this Special High Performance (SHP) 440 low carbon steel. SHP 440 carbon steel with a maximum carbon content of 0.18% by weight C through a cold rolling process with size reduction variations of 10, 20, 30, 40, 50, 60 and 70%. The results showed that the most optimum increase in hardness values occurred in rolling with a size reduction of 70%, namely HB: 98 and increase of 16% from the initial hardness value, namely HB: 81.67 with a grain size of 8.20µm or decreased by 24.44% from the initial grain diameter of 10.85µm. In this research work it has been found that the greater the percent reduction in rolling size the hardness value of the SHP 440 low carbon steel will be higher

Fabrication of the Ti/SiC Based Composites by Self-Propagating High Temperature Synthesis

Metal matrix composites (MMC) consists of matrix and reinforcement. Aluminium (Al) and titanium (Ti) are mostly used as a matrix, while ceramics like silicon carbide (SiC) play role as a reinforcement where magnesium (Mg) act as wetting agent. Al/Ti alloys often used in the applications of powder-shaped. Nevertheless these materials are very suitable for the processes that are using a simple and novel method called self-propagating high temperature synthesis (SHS). Based on it, some of the advanced materials such as alloys, advanced ceramics and intermetallic compounds have been focused on SHS process. The SHS compacting process is carried out in stages according of the temperatures helping by compacting force applied. Our research work will be focused on the fabrication composites based Ti/SiC by using SHS process. The microstructure of the Ti/SiC based composites was investigated by using optical microscope. The micro-hardness testing device has been used to determine the mechanical properties of Ti/SiC based composites. The relationships between reaction of the Ti and SiC have been investigated to obtain the value of the composite properties and the bond between Ti and SiC. Ti/SiC based composites were obtained with improved properties

Aluminum based Composites by Severe Plastic Deformation Process as New Methods of Manufacturing Technology

Composites a material was developed to replace metal and alloys, because of the properties such as light weight and unique mechanical properties. Processing of aluminum-based composites has been developing by new manufacturing technology, namely severe plastic deformation (SPD), to produce unique of mechanical properties. Some of the methods used are; equal channel angular pressing (ECAP), accumulative roll bonding (ARB) and multi-axial forging (MAF). The results of some of these methods were compared with the latest method of new SPD, namely: repetitive press roll forming (RPRF). Based on grain morphology and mechanical properties, the result of RPRF has superior to another method. The properties produced by SPD technology was varies, the highest of hardness produced by RPRF process was 88 HV10, ECAP produced 65 HV10, MAF was 46 HV10 and ARB reached 50 HV10. While the highest of tensile strength produced by MAF was 237 MPa while the RPRF process just only around 147 MPa, but the ultrafine grains just only produced by RPRF method which is 0.9 μm, compared to other methods: MAF 1.2 μm, ECAP 5.7 μm and ARB is not so far with MAF that is equal to 1.4 μm. The RPRF process can be recommended for the interest of the aluminum-based composite materials processing industry. Because currently some component product by industries have been substituted from metal alloy materials to metal-based composites