Concept engineering of a cooling water treatment system and sealing pumps of a mining concentrator (LA19)

ISSUE

A filtration system consisting of a pre-filter, filter element and an in-line strainer was installed in a mining plant operation; however, the filtration systems have clogged on its start-up operation. The system intake source is from a tailing pond of the iron ore concentrator's overflow. First, it was necessary to determine the possible causes of the initial clogging of cartridges of the water screen filters. Next, it was necessary to determine the type of separation equipment best suited for the system for efficient and robust results. The current system can not perform well because in-line sieve is clogging and generating a system operational failure. Even Tests with 2.5 times more open filter elements provided similar results of quick clogging.

TECHNOLOGICAL CHALLENGE

Determining the root cause of the clogging and design a suitable separation system to treat the water lake so it will not clog. the treated water needs to meet the quality standards necessary for sealing the pumps and plant cooling system.

RECOMMENDED SOLUTION

Firstly, STS Canada has conducted water analysis for water characterization which made it possible to determine the root cause of the screen clogging. The tests have indicated that the fineness particles were the cause of the screen clogging. Secondly, the separation technologies were evaluated using a technical methodology based on the design criteria gathered from the system considerations. The objective of technological evaluation is to select the best technology for the application. Moreover, the water analysis indicates significant contaminations of heterotrophic aerobic and anaerobic bacteria (BHAA). The bacterial contamination can cause severe problems with the treatment system such as fouling and enhancing corrosion rates. The addition of a bacterial control system was recommended in the water of the sealing and the cooling water system. STS Canada used a similar approach to assess and select a method for bacterial control in the water.

RESULTS

The assessment of separation technologies indicated that a liquid-solid separation unit can meet all design criteria except for bacterial control in lake water. The addition of a system for bacterial control was therefore necessary. This technology needs to prevent corrosion acceleration since all pipes and equipment in the plant are made of carbon steel. Therefore, the plant must install new liquid-solid separation equipment as well as a bacterial control system on the water circuit for sealing the pumps and cooling the plant.