Producing Clean Coal from Western Canadian Coalfields using the Water-Based 'Roben Jig' Process – Application to an Industrial Setting

Key Researcher(s):  M. Mackay

Project ID:  2018-034

Key Research Organization(s):  Canadian Carbonization Research Association (CCRA)

Project Location:  Southeast BC

Strategic Focus Area:  Minerals

Summary



This project is refining a new water-based process for cleaning metallurgical coal samples prior to coke quality assessment. Information about previous phases of this project can be found here and here. This phase of the project will include final pilot tests of samples in a larger scale coke oven to  assess complete coke characteristics and quality.

The Need

Coal is BC’s largest export commodity. In 2018, metallurgical and thermal coal production generated $6.31 billion dollars for BC (view report). Innovative technologies are needed to help this sector maintain its international competitiveness.

Samples of metallurgical coal — used to make coke, an essential ingredient in steel production — are ‘washed’ before quality testing in the laboratory. Coal from BC’s coal mines contains ash which must be removed to produce a clean sample for accurate coal and coke quality characterization. This step in the analysis process is vital to accurately assess the economic value of a deposit and must be reliable.

Currently, coal samples are analyzed using the float/sink method which uses organic liquids such as white spirit, perchloroethylene (PCE) and methylene bromide. These organic liquids can have a negative effect on testing coking coal quality and potentially expose laboratory technicians to carcinogenic materials.

An alternative and effective water-based washing method, that could provide comparable results to that from an industrial coal-washing plant, would remove the need to use organic liquids in the process and the associated health and environmental risks.

Project Goals

This project is designed to build on two previous phases (project 2016-067 and project 2017-013) of pilot testing of the water-based ‘Roben Jig’ process with an upgrade to a larger scale coke oven.  After using the ‘Roben Jig’ washing process this project will assess the complete coke characteristics and quality for a broad range of coal types found in BC coal fields and determine if this coal’s quality is equivalent or superior compared to traditionally washed methods.

Project Benefits

The main benefit of washing coal samples using the water-based Roben Jig is to remove the safety risks associated with the handling and use of organic liquids such as PCE. PCE is a known carcinogen and poses a safety hazard for laboratory operators who must handle the chemicals carefully to avoid exposure.

Investigations have also found that PCE can influence the properties of coal being tested, reducing the reliability of the test and perhaps leading to over- or under-valuing of a potential coal deposit.