#TITLE_ALTERNATIVE#

• Main Author: GUNTORO (NIM : 22108030), DONO
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/20042
• Institution: Institut Teknologi Bandung

Deposit of lateritic nickel was resulted from advanced weathering of Ni-silicate bearing ultramafic rock. It generally existed in area with tropical to subtropical <br /> <br /> <br /> climate. Tropical climate in Indonesia resulted in intensive weathering process, therefore some areas in eastern Indonesia have lateritic nickel deposit. Nickel <br /> <br /> <br /> concentrating process at lateritic nickel deposit was controlled by several factors, which were bad rock, climate, topography, ground water, mineral stability, <br /> <br /> <br /> element's mobility, and environmental condition which affected solubility of mineral. With that kind of control, there were three types of lateritic, which were <br /> <br /> <br /> oxide, silicate clay, and hydrosilicate. This research was more focused on mineralogy of lateritic nickel deposit, its characteristic, its types, and physical properties included grain size, bulk density, and moisture content. The sample for this research was taken from out crop and outcome of drilling. Based on the recapitulation of XRD analysis, there were 10 groups of mineral. In horizon of saprolite, there were hydrous mineral of Ni-silicate, while upper horizon had group of hydroxide minerals, therefore lateritic nickel in area of study was predicted as transition between lateritic hydrosilicate and oxide. If sort base on each horizon laterite deposite, then the top soil, limonite, and <br /> <br /> <br /> transition part were dominated by hydroxide and silicate minerals. While, the horizon of saprolite was dominated by serpentine group of mineral. Based on the result of XRF analysis of the bedrock outcrop samples which were <br /> <br /> <br /> considered fresh (weak alteration) in every block resulted in percentage of several substances, some of them were Ni as many as 0.46 - 1.10 %, Fe2O3 10.95 - 13.44 %, SiO2 38.65- 43.86 %, Mg 29.38 - 31.54 %, Al2O3 1.66 - 2.22 % and Cr2O3 0.52 - 0.62 %. Petrography analysis on thin section showed mineralogy that composed bedrock consisted of olivine, ortopyroxene, and clinopyroxene, as well as altered mineral in form of serpentine. Therefore it could be classified as rock of Lherzolite, Wehrlite dan Olivin Websterite. The rock was altered ultramafic rock (serpentinit). Based on physical behavior analysis on the horizon of top soil, it had grain size relatively sand 60% and clay 40%, bulk density about 1.43 - 1.68 ton/m3 and moisture content 14.55 - 26.77 %. Horizon of limonite had grain size relatively sand 78% and clay 22%, bulk density about 1.54 - 1.69 ton/m3, and moisture content 21.15 - 32.46 %. Horizon of saprolite had grain size relatively sand 96% and clay 4%, bulk density about 1.34 - 1.36 ton/m3, and moisture content 27.62 - 44.57 %.