Water saving log washer improves diamond recovery

Process equipment marketing and manufacturing company QVA Process Technologies has delivered a log washer to a Botswana diamond mine, which will offer significant savings through water consumption and reduced power.

The unit, ordered by project management company ADP Projects, will be used to break down and wash competent clay briquettes, which is thick clay that is formed in crushing, and will also radically improve diamond recovery, as it is difficult to reclaim diamonds from kimberlite with clay properties.

QVA, essentially known to the industry for itlargest crusher in indias range of teetered bed separators for the coal industry, have designed and supplied the equipment that will remove heavy clay lumps that are found in the tailings.

High pressure toothed roll crushers form the kimberlite into clay briquettes that encapsulate the dbuy block making equipment in canadaiamonds. The current rotary scrubbing system does not have the capacity to liberate or break down this material. This is fundamentally owing to a too gentle scrubbing action, which allows material to pass through the system and land on the dump, creating the losthe industrial process in minings of diamonds.

Also known as the rock washing machine, it is a significantly more intense process than conventional rotary scrubbers and uses far less water and power. Maintenance and capital layout is also considerably less than current operating systems. The log waore stockpile design for copper oresher recirculates water constantly, allowing mines to save water.

The log washer has two counter rotating shafts with blades arranged in a spiral pattern. These shafts rotate in an angled tank that has water injected to the lower portion.

Feed water transportcrushing plants made in chinas the liberated fines out of the rear of the machine, while the blades attrition liberate and transport the nonfriable ore, which contains diamonds, up the trough and discharging it onto a secondary washing screen, without breaking the diamonds.

Locally, log washers have been used in the copper mining industry. Traditionally they have been applied to more humble endeavours such as washing gravel in the construction industry.

Hundreds of stone producers in the US and Europe use log washers for decorative building purposes. However, the design and application of this particular machine is innovative.
It is arguably the largest unit of its kind working in Africa and has been designed to treat 350 t/h of dump material.

QVA believes that this machine will prove superior to the traditional method of kimberlite treatment and, in the future, will become the industry norm.