Cost Analysis. Always check your cyanide consumption level and work within range. Whenever, you are treating different ore from a new pit. Make sure you do cyanide consumption test to have a range to work with. On the plant cost budgeting, cyanide account for a higher fraction.

Security: As a metallurgist although there are securities on the plant, you are responsible to maintain "gold free exposure". Where there can be possible visibility of gold on the plant (gravity table, Knelson concentrator, etc.), you try as much as possible to clean the place in other to reduce exposure rate and alarm for theft.

Production: The metallurgist is there for production. Always try and work within the production target. Make sure that the mill throughput is always attained. When a different material is fed and cause downtime, raises alarm with your subordinate and sees how to blend or increase throughput. Be very careful with tailings disposal regulations since it can cause a big challenge.

Supervision and Team work: As you can't do all the work yourself, that is why you have a group of people you are working with. Always team up. Always walk round and see what the technicians are doing and make sure they are within the SOP of the company. Find correct medium to address issues when they come out.

We read some papers on basic flotation cell maintenance checks. I realize that you are talking leach tanks but as a starting point there are some similarities between floatation tanks and these.

Murphy, B, Heath, J L and O’Connell, S, (2014) Maximizing value through maintaining your flotation equipment, in Proceedings 12th AusIMM Mill Operators Conference 2014, pp 71-76 (The Australian Institute of Mining and Metallurgy: Melbourne).

Jalili, A, Murphy, B and Tolvanen, P (2015) Unlocking value through flotation equipment maintenance, in Proceedings of 47th Annual Canadian Mineral Processors Conference 2015, pp 234-243 (Canadian Institute of Mining and Metallurgy: Ottawa).

Both have basic check list though the second one may be of more interest to what you are trying to achieve as it discusses (and gives an example) of ways of using data to improve on traditional maintenance practices.

Regular Plant Metallurgist' checks includes : mill grind size (P80 of COF and PSI), leach feed grade, leach tails grade and PSI, leach feed density, leach tank carbon profile, leach tank pH, CN and Dissolved Oxygen Levels. There should also be a regular leaching efficiency using bottle roll tests and carbon audit which some activated carbon offers free as part of their supply package.

We already do leaching in our tanks on regular shift basis, how will the efficient leaching checks influence the ongoing process because all parameters have already been set for the leaching process based on bottle roll test results before the beginning of the month. How frequent should the leach test be done and how should we alter our set points based on the results.

Thanks a lot for the other checks you suggested. They are well noted.

Some ideas for standard ongoing checks to improve plant performance:

Carry out bottle roll tests on the tails adding a lot more cyanide, and monitor the extra leaching. This will give you an easy daily indication of the efficiency of your leach. The challenge is then to decrease the level of easily leachable gold by increasing the cyanide addition to the tank farm. This method can also be used to test if you can reduce the cyanide addition to the tank farm, by simply reducing the cyanide addition for a day, dependant on residence time, and monitor the bottle roll leach results.

I agree with all the checks listed above, and note that these are important. It is always a good idea for the process engineer to carry out spot checks. Often poor recovery is associated with not taking due care of the basics.

Do quality control checks on the new virgin carbon, especially for hardness and shape, as excess platelets will lead to a higher carbon loss, and gold losses on the fractured carbon.