The mesh profile used in the trial test was 32% for 0.8 mm mesh and 68% for 0.3 mm mesh. Figure No. 2 shows the mesh distribution. Figure 2 – Dewatering screen Methodology and Pilot Plant The validation methodology begins with laboratory testing of 5 kg samples to confirm whether clay removal is possible through dewatering tests at different mesh sizes: 150 µm, 212 µm, 300 µm, or 500 µm. After confirming clay removal and a high probability of successful dewatering, a 40 kg semi-pilot test is conducted under varying conditions of screen opening, time, percentage of open area, amplitude, and dilution percentage. During the semi-pilot test, the metallurgical and geotechnical moisture content, mass recovery in the oversize material, and the removal of ultrafine material (less than 20 µm) and clay percentage are determined. Based on this target data, detailed engineering is performed for a 50 tph pilot plant, including dilution systems, classification screens, dewatering hydrocyclones, and recirculation pumps. The pilot plant has sampling and maintenance systems to be tested under different operating conditions and with varying clay contents and qualities. This testing confirms the metallurgical and geotechnical moisture requirements for the construction of the dam or paddock, validating the geotechnical requirements. Controls were also made of the 200-mesh screen, apparent density, standard and modified Proctor density, and water permeability. During testing, mass and water balances are performed, along with the classification efficiency of the screen and hydrocyclones. Water removed by the overflow is also analysed, and the option to recover it using a high-compression thickener and recirculate it into the process is explored to optimize water consumption. After the pilot phase is completed, a pre-feasibility, feasibility, and detailed engineering study is conducted, along with the operational readiness of a 1000 tph industrial plant with its complete automated operation and control system, including water recovery and clean sand generation systems. This study will be evaluated for potential implementation. Even with the finest screens some of the 75 μm um material will pass to screen u/s. To minimise the losses the screen is operated with a deep bed and the screen u/s cycloned to remove
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