In most cases, the type of collector can be pre-selected based on production practice and research experience, or it can be determined in preliminary tests, and does not necessarily need to be a separate test item.
The dosage of the reagent can be tested using two methods. One method is to keep other conditions constant and only change the dosage of the collector (e.g., 20g/t, 40g/t, 60g/t, 80g/t), conduct tests separately, and then find the appropriate dosage. The second method is simpler: in a unit test, the necessary dosage of the collector is determined by adding the collector in stages and skimming the foam in batches. First, add a small amount of collector, skim off the first batch of foam, and after the foam mineralization weakens, add the second portion of reagent. The amount of the second portion can be equal to or less than the first portion, depending on the specific situation. Skim off the second batch of foam, and so on, until the flotation endpoint is reached. Then, chemical analysis is performed on each product of the process to calculate the cumulative recovery rate and cumulative grade, in order to determine the desired recovery rate and grade and the amount of collector to be used. This method is often used for preliminary tests.
If several collectors are used in combination, the collectors can be divided into several groups with different proportions, and then each group can be tested.