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 small pilot-scale coal preparation plant does not wash all fractions concurrently. The coarse, fine and ultra-fine coal fractions are processed individually through stand-alone circuits. This has allowed ALS greater control of the sample processing stages. These stages are outlined below.
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. Comprehensive coal characterization is provided on simulated product by sub-sampling the products and rejects and processing the coal through ALS' extensive laboratory network