Q3. An ore sample consisting of CuFeS2, ZnS and FeS2 is taken from the concentration unit of a plant. Series of some tests are applied such as chemical analysis, optical image analysis (Clemex), point counting and MLA analysis. A liberation test is carried out and the results are given below recorded from point counting method under microscope.

a) Calculate the liberation degree of sphalerite (10 pts). b) From the optical image analysis, the amounts of CuFeS2, ZnS and FeS2 are measured as 33.56%, 14.20% and 52.24% respectively (the values assumed as volumetric). According to these values calculate the percentage of Zn grade by weight (15 pts). c) MLA is also applied to the same sample and minerals amounts are measured. Zn % is calculated as 9.9% from sphalerite mineral. But, from the chemical analysis of Zn % is calculated as 10.60%. Liberation degree is also calculated from MLA and Clemex for sphalerite such as 61.1% and 59.8% respectively. Compare the accuracy order (like x method >y method> z method) in terms of Zn %, amount of sphalerite and liberation degree values obtained from chemical and all mineralogical analyses (point counting, Clemex and MLA) and explain which methods results are most reliable for both Zn %, sphalerite and liberation degree determination (15 pts).