Multotec supports drive for quality coal sampling

With the current drive to encourage coal suppliers, particularly those providing coal to Eskom, to conform to a specific quality of coal, leading mineral process solutions provider Multotec has been approached from several quarters of the industry to address the focal issue of coal sampling.

“The fundamental purpose of collecting and preparing a sample of coal is to provide a final representative and ergonomic amount, which when analysed, will provide a result that is fully representative of the quality of the whole, whether daily production or a batch sample,” says Multotec’s Rolf Steinhaus.  “This is critical to allay concerns that out of specification coal coming from smaller suppliers might affect industrial processes, specifically the operation of coal-fired power stations, in terms of its combustibility and related efficiency. Coal clients are demanding to know exactly what they are paying for and reliable results are needed on which to base decisions.

“The coal fed into coal-fired power stations has to be of a quality that falls within a specific range and the onus must fall on the supplier to comply with this requirement. Colleries and quarries are paid and possibly even penalised based on the quality of the coal they supply and the customer has the right to reject sub-standard coal. There is a strong move to ensure that such coal is identified in good time, well before it enters the buyer’s stockyard.

“As an internationally leading supplier of coal sampling equipment, Multotec has watched this issue unfold in South Africa over the past 18 months and we see one of our primary roles as assisting the smaller and emerging coal suppliers to sample their coal effectively and accurately.”

Henning says the best approach is to sample the coal as it is being loaded for shipment by road or rail. Samples should be marked with the time and date they were taken and also sent to an independent third party laboratory for analysis verification.

“Eskom has called upon us to consult and assist in this area and we are well placed to assist with the required methodology or protocol based on our many years of experience since 1987,” he says. “In recent months Multotec teams have visited numerous sites to assist with possible solutions.  We’ve recently supplied close to 15 sampling stations to both large and small suppliers in local coal industry and more are on order — an unprecedented number in such a short period of time. These sampling plants adhere to all internationally recognised standards and stringent bias testing ensures sampling is representative in aspects such as particle size, moisture content, ash content, CV, and other specifications as may be required.

“We’re fielding a lot of interest from the ship loading arena and one of our biggest success stories here is at the Richards Bay Coal Terminal,” he says.

Exciting results

“Our ongoing investment into research and development, in conjunction with our licensor Siebtechnik GmbH in Germany, is showing exciting results. Multotec has manufactured and supplied sampling equipment under license to Siebtechnik since 1987 and we have also collaborated with the Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australia's national science agency to improve our products’ performance and achieve as near a bias-free result as possible with our sampling equipment.

“Further strengthening the integrity of our technology, some of our sampling equipment designs are sent for critical evaluation to international sampling gurus for accreditation. We believe our coal mechanical sampling technology is of the most advanced available in the industry today and customers throughout Africa and Australia confirm this via feedback.  Our sampling equipment is also used in various other mining sectors, such as iron ore, base metals, gold, platinum, HM sands and manganese amongst others.

“Multotec’s in-house design team has remained abreast of conveying and processing technology to ensure that our sampler designs are compatible with the latest innovations and we’re constantly examining ways to improve the performance and life expectancy of our equipment via our generous R & D spend. Beyond being sampling equipment suppliers, we are primarily solution providers.”

Henning points out that sampling has also become a big focus internationally across a number of commodities, in keeping with the need to ensure industrial processes work optimally. He cites this as another reason for the good growth in demand for Multotec’s sampling technology particularly in the last 7 years.

Technology

Multotec’s Hammer Sampler was originally developed and successfully installed by Siebtechnik in Germany in 1964. Owing to the ease with which it can be installed or retrofitted to take representative samples from a moving conveyor belt, it has become very popular internationally.  This sampling equipment incorporates all the process and design knowledge gained during Multotec's and Siebtechnik's long involvement in the area of dry sampling and recent additional work done by CSIRO using discrete element modelling.

The company’s cross belt sampling offering include primary cross belt samplers, cross-stream samplers, custom-designed mini sample feed conveyors, rotating plate dividers for continuous or timed dry material splitting, as well as jaw, impact and cone crushers and carousel/product indexer sample collectors and other products to provide a total quality solution.