1. Cost-benefit Analysis
It’s advisable that the ore veins of Tanzania NHM Company adopt the waste-lifting stoping mining methods. The ore bodies of different thicknesses have many similarities in the technology of waste-lifting stoping; and the labor and material costs that every mining cycle consumes are basically the same. The difference is that ore capacity from ore bodies of different thicknesses. Therefore, for the ore bodies with different thicknesses, we first count the labor and material costs of the sum of per ton ore and waste rock by the mining range of 1.1 m, and then calculate the mining costs of ore bodies with different thicknesses according to the ore capacity obtained by each mining cycle. The mining cost composition of NHM Company adopting the technology of waste-lifting stoping as follow:
|No.||Cost Items||Unit||Unit Consumption||Unit Price |
|Unit Cost |
|III||Wages of production workers||10.5|
|IV||Ore + rock direct operating costs||I + II +III||17.15|
|V||Ore + rock management costs||8.1|
|VI||Ore + rock construction team contracting profit||（IV + V）×20%||5.05|
|VII||Mining workshop manufacturing cost|
|Actual thickness of mineral vein:0.75m||30.3|
|IX||Total cost of mining||40|
2 Mineral processing costs
|Items||Unit||Unit Consumption/tons||Unit Price |
|Unit Cost |
|Total consumption of a year||Total costs |
|V||Finance and others||RNB||0.25||11.3|
3. Total Costs
According to the above calculation of mining and dressing costs, the unit overall cost of each mining and dressing is about 114.93 dollars per ton and the annual total costs is about 5,172,100 dollars
4. Sales Revenue
For this design, referring to the preliminary test preparation, the recovery rate of gravity separation is 50%; the gold leaching rate is 96.87%; the loss of the gold-melting Electric technology is 2% and the recovery rate of gold-smelting is 98%. Given the above data, the total recovery rate is（50%+50%*96.87%*98%）*98%=95.52%, namely, annually recovering 866.1kg gold.
If the sale price of gold is 35 dollars per gram, the annual sales revenue is about 30,313,500 dollars, tax without consideration.
In light of the above data, we can estimate that the annual return is 25,141,400 dollars and the profit of a unit of raw ore is 558.7 dollars per ton.
These data in this cost-benefit analysis are all pre-tax information, you can calculate the after-tax ones by yourself in accordance with local tax condition.