It's time to answer your questions regarding in situ copper leaching. If you can not find your answer here you can always send me an email and I will try to answer your specific questions.
What is in situ leaching?
To answer that we have to break it down into its components:
First let us define leaching. Leaching is a well known process that is commonly thought of as water or other solutions that remove soluble material from rock, soil or even water pipes. This process as it commonly relates to the mining industry uses the process to extract economic minerals from ore. For most processes the solution will not be water but instead a weak sulphuric acid solution is used for dissolving copper. Other minerals such as gold will use different solutions.
Second let us define in situ. Commonly this is defined as "in place" or "in position". This means that the material (rock) has not been moved. Most mining processes require moving a lot of material and much of that material is not even processed for its minerals. Therefore, in the case of mining this means that the rock is not moved at all whether its ore or waste. Why waster all that energy and expense if you don't have to?
So finally we can answer the question. In situ leaching is the process of leaching minerals without having to move the material (rock).
Why is in situ always in italics?
Well there is probably no right or wrong answer as to whether or not it should be italicized. The in situ comes from latin and historically latin terms are italicized. However, language changes over time and the strict rules regarding italicization have softened and it would probably not be wrong to write the term in standard text anymore.
What are the expected recovery rates?
Defining ore reserves can be a challenge with this type of extraction technique. Other mining processes are well established, therefore a body of knowledge already exists in regards to the expected recovery rate. This figure can then be refined by testing bulk samples under different conditions. However, it is not possible to bulk sample a proposed in situ leaching deposit. You have simply destroyed its nature by removing it from the ground. Instead, pilot tests would be needed to test the recovery rates in situ. But that is not really practical because even a pilot test is expensive and requires a lot of permitting. Laboratory tests may be the first step in trying to determine both your recovery rate and acid consumption.
What you can expected however is that your recovery rate will fall between 50% and 100% of the acid soluble copper. Or to put it another way it will fall between 35% and 70% of the total copper if it is all leachable copper. This is a large variance and that is why there is a need for laboratory and pilot tests.