#TITLE_ALTERNATIVE#

• Main Author: PURWA LAHARDI (NIM 12103018), NIRWAN
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/8823
• Institution: Institut Teknologi Bandung

Nickel laterite is ultramafic rock weathering product. Nickel precipitate forming involves leaching process, element transportation, and the forming of new minerals. The media of leaching process and element transportation is underground water.<p> <br /> <br /> <br /> The observation was done in mining operation area of PT. XYZ, Tbk, which is located in Moronopo, East Halmahera, North Maluku.There were obstacles that were found in improving production effectiveness and efficiency. One of the obstacles was production value which was different with exploration data. The aim of this observation is to know the degree of that difference and factors that caused the difference.<p> <br /> <br /> <br /> Nickel was graded more or less than its true grade. The lowering nickel grade in observation area was -0.20%. The lowering of this grade was followed by the increasing of Fe grade and the lowering of bacisity value. The increasing of Fe was 4.34% and the lowering of bacisity was 0.10.<p> <br /> <br /> <br /> Value difference in observation area was caused by several things, one of them was its bedrock factor. The condition of bedrock types (which was peridotite, both dunit and serpentinit that was spred in some places), was varying. Bedrock (ultramafic) could also experience serpentinization process before experiencing lateritization process. The occurrence of serpentinization process in observation area was in moderate to high degree. Serpentinization degree influenced the continuity degree in saprolit zone.<p> <br /> <br /> <br /> Other factor that caused value difference was topography condition. Dissolving and transportation media involved underground water. Topography condition would effect underground water behaviour in leaching process. Weathering intensity on bed rock was also effected by rain water quantity that penetrated through bed rock cracks. The lowering of nickel grade took place at an angle range between 9 degrees-21 degrees and the increasing of Fe grade occurred at an angle range between 9 degrees-15 degrees.