SURVEY OF HYDROCYCLONE OPERATING PARAMETER INFLUENCE ON SLIME CLASSIFICATION PERFORMANCE AT PT AMMAN MINERAL NUSA TENGGARA

• Main Author: WAFI IRAWAN (NIM : 12513061), FIKRI
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/22162
• Institution: Institut Teknologi Bandung

PT Amman Mineral Nusa Tenggara (PT AMNT) is one of the mining companies in Indonesia with copper concentrate as its product. Currently, PT AMNT has a processing capacity of up to 120,000 tons/day. From historical survey data conducted by companies in 2009, 2013, and 2016, when the factory processed stockpile ore with WiBM hardness value of more than 12 kWh/ton, it was found that slime (very fine particles, corresponding to -75&#956;m) accumulation in the grinding circuit quite high. This is due to two things. First, there is a comminution processes that generates slime in huge amount and the second is hydrocyclone is not performing well to classify slime. These fine particles should have come out as overflow and enter the flotation concentration process. Instead, these slime report to undeflow and become recirculating load in the grinding circuit. <br /> <br /> <br /> A series of experiments was conducted to determine the effect of hydorcyclone operating parameters which are percentage of solid feed and feed pressure on slime classification performance. Intially, a number of samples were taken directly from the plant with a solid percent target of 63, 65, 67, and 69% and feed pressure of 30, 38, and 45 kPa. Then a sieve analysis at fractions 19,000 to 38 &#956;m and mass balancing using JKSIMMet application were conducted and then plotted on the partition curve or Tromp curve. Then hydrocyclone efficiency was modeled using Plitt model to assess the best operating conditions. Samples were then characterized by XRD, mineragraphy analysis, and assay analysis. Feed samples were characterized by XRD and mineragraphy analysis in the form of polish section, thin section, and grain dispersion to determine the mineral and its inclusions. Lastly, all samples Cu and Au coassay were analyzed at fraction of +212 &#956;m, -212 &#956;m +75 &#956;m, and -75 &#956;m to find the distribution of valuable minerals. <br /> <br /> <br /> From the results of experiments conducted, 69% percent solid was not achieved expected due to reduction of solid throughput at that time so the feed solid percentage decreased to 66%. Then it is obtained the best variation at 63% feed solid and 45 kPa operating pressure. On the overflow, Cu and Au are mostly found at -75 &#956;m fraction. While on the underflow for Cu found in the fraction of +212 &#956;m while for Au tends to fluctuate.