ALS operates two pilot-scale coal preparation plants. The larger plant processes raw coal samples of between 1.4 to 20 tonnes. This plants accurately simulate a broad range of full-scale coal preparation plant processes. It has significant value in that it can evaluate the washability behavior of a coal and produce washed products in a way that is closely aligned with the product that might be achieved from an operating mine.
The pilot-scale coal preparation plants are employed to achieve three main goals:
The pilot-scale coal preparation plant includes appropriate equipment to handle and process coal through various coarse, fine and ultra-fine circuits. The plant does not wash all fractions concurrently as in a typical wash plant. After separating the coal into the required size fractions, the coarse, fine and ultra-fine coals are processed individually through stand-alone circuits. This allows for greater control of the sample processing stages.
The following provides guidance on the processing of a coal and the equipment available within the pilot-scale coal preparation plant.
The plant contains appropriate control systems including nuclear density gauge, a full suite of density tracers, and automatic medium density control based on CITEC SCADA system. There are also two 10 tonne product bins, 1,200 mm and 600 mm Kasson screens, horizontal vacuum belt filter, water recovery and recycling systems. An on-site cold room allows for sample storage to reduce the degradation of the coal’s properties.,
If there is limited coal washability information on the plant feed, ALS Coal is able to collect a sample to conduct a full washability analysis which can be used to identify the target densities to meet yield and target ash values. Each of the pilot plant products are typically dried, weighed and subsampled for ash percent. This provides guidance on the product ash and yield. A simulated overall plant product can be targeted by proportional blending of the product streams
Finally, comprehensive coal characterisation is provided on simulated product by sub-sampling the products and rejects and processing the coal through ALS’ extensive laboratory network.