News Articles

Portland Bulk Terminals, a Canpotex facility for the export of Potash is managed by Kinder Morgan Bulk Terminals Inc. Located in Portland Oregon, the terminal is the site of a recent Belt Scale Permanence test. The test, the final part of the NTEP trade approval process, has established High Precision Belt Scales manufactured by Australian Company, Control Systems Technology Pty Ltd (CST) as the preferred method of weight determination for the export sales of Potash.

Bulk Solids Handling - Vol 22 (2002) No. 6

Export sales of bulk materials have long been conducted on the basis of ships draft survey. It has become well known that precision of accuracy is quite variable depending upon wave action, the age of the ship and hence the precision of the original volumetric survey and the amount of time allowed for the survey process. The repeatability of ships draft survey can vary between +-0.5% and +-2.0%, while offset errors due to the quality of the ship's original survey are of unknown size. If the accuracy of the whole ship survey is questionable, the accuracy of partial loads is even more in question. This is why Canpotex has chosen to base all of its export sales upon weighing by High Precision Belt Scales by CST. Canpotex is the world's largest potash exporter, and is an international marketing and distribution company wholly owned by the Saskatchewan potash products: Agrium Inc., IMC Canada Ltd., and Potash Corporation of Saskatchewan, Inc.

CST has worked closely with their North American agent, TD Micronic, Inc. of Vancouver, BC in having their belt scales approved for trade use in the USA and in Canada. CST had completed NTEP laboratory testing and also the initial round of field testing at Portland Bulk Terminals and then on 12th August 2002 the final Permanence test was conducted.

The National Type Evaluation Program (NTEP) in the USA involves laboratory and field test. The field tests require that 3 consecutive test loads be passed over the belt scale at a flow rate between 35% and 98% of capacity with an error not exceeding 0.25%. The belt scale at PBT is rated at 5000 t/h and it was tested with 600 t loads at a flow rate of 3500 t/h. The reference scale upon which the 600 t loads were pre-weighed was a Toledo track scale with an accuracy equivalent to 0.02%. The normal permanence test period is six months, however the period since the initial tests had stretched out to 13 months. The belt scales is required to perform to an accuracy of +-0.25% at the time of initial tests and again in six months, or in this case 13 months later.

The performance of the belt scale was very convincing at the initial tests, returning errors of -0.04%, -0.03% and -0.01%, while a test rejected by NTEP officials as not sufficiently within the 35% to 98% flow range showed an error of -0.08%. The later tests 13 months later, without any adjustment or maintenance, yielded a very repeatable group of errors or 0.12%, 0.12% and 0.01%. The results were the subject of much favourable comment by the testing officials who were ready to simply restart the tests if the 13 month period had proved to be a problem, as indeed, it is well beyond the required 6 month period. The error of 0.12% high represents a calibration drift in the order of less than 0.01% per month, a drift which is likely to be due to a reduction in the diameter of the tail pulley used for tachometry. On the 1000mm tail pulley which is affected by rust scale, which is in turn related to the corrosive nature of potash, a reduction in diameter of only 0.5mm would account for this level of calibration drift.

While the capital outlay on one of these highly stable belt scales is more than many other units on the market, the low cost of maintenance and the efficiency of certification tests will yield cost savings which will repay the capital over and over during the life of the equipment. More importantly, the high precision of the belt scales is also likely to bring in the right revenue when compared to the relatively variable results available from ships survey.

Bulk Solids Handling - Vol 22 (2002) No. 6

Since it was established more than 20 years ago, NSW-based company Control Systems Technology (CST) has been specialising in precision, high-end belt weighing systems.

According to CST’s manager Ian Burrell, CST has a unique engineered method of analysing and recommending custom-made belt weighing equipment for each specific application.Mining Journal Feature - Trusted Names - Vol9 No.11 (2004)

“CST does not compromise its application engineering approach, but designs systems which are specifically tailored to each application using professional mechanical engineering design principles,” Mr Burrell said. CST’s in depth understanding of the fundamentals of weighing technology means their weighers are usually, larger, heavier and therefore can be more expensive than those offered by competitors..

“Those customers who have realised the overall lower cost of ownership of a CST system and have selected CST as their supplier have universally enjoyed an unusually trouble-free and high confidence experience with belt weighers, with reliability, low maintenance, and consistency of accuracy key features mentioned in our customers’ favorable responses.”

As a result, CST has become the supplier of choice for many of the larger mining companies who understand the benefits of using CST's high-quality solutions.

As well, CST is also able to provide belt weighing consulting and engineering services to customers concerning their existing equipment.

“We are able to conduct audits on belt weighing applications and are able to troubleshoot troublesome applications, explained Mr Burrell. “We can provide a high level of service from our teams of engineers and technicians in Sydney, Mackay and Perth.”

Mr Burrell said BHP Billiton is one of many companies with whom CST has a long term relationship in supplying and servicing belt weighing equipment and systems.

“We have supplied reliable belt weighing products for the critical accuracy ship loading and stock management areas at Nelson Point, Finucane Island and Port Hedland.”

Mr Burrell commented that the mining industry has specific needs and requirements for weighing equipment. “This includes high reliability and rugged equipment which is readily understood with minimum technical expertise. Training for support staff on remote sites is an important ingredient supplied by CST, which ensures that the weighing equipment on site operates smoothly and efficiently, minimising down time.

“We specialise in high-quality solutions. We aim to be competitive, but do not work to a price formula, or generic designs and specifications which fall short of giving the customer the weighing solution they need. Our well-engineered equipment means high reliability and low maintenance, and therefore minimum disruption to continuous operations. While belt weighers are a small initial cost component in site and plant development, in terms of site management’s confidence in actual site input and output, over the long term they are critical’.

CST customers are fully supported by sales and service offices throughout Australia, staffed by highly trained and experienced technicians.

Mining Journal Feature - Trusted Names - Vol9 No.11 (2004)