Design a preliminary flowsheet

With all the information obtained in the metallurgical tests can be elaborat ed a possible flowsheet with the optimum recovery. Also, must be done the mass balance in order to have some information for the equipment to be used. 

In this part must no be considered costs of investment, only will be important the maximum recovery to be obtained. Each flowsheet must be good calculated and proposed because will be the base of the economic evaluation and engineering. It is important have alternatives for modifying the proposed flowsheet because could be necessary low the costs of investment trying to maintain the same recovery or perhaps, increase the recovery with a major investment. The latter aspect must be evaluated in order to verify its rentability.

2.6 Economic evaluation.: This is the key part for choosing the design of a plant. For the proposed circuit and each alternative must be considered the following aspects.

a. Total cost.: This part considers the total cost of all the equipment to be employed, and costs of building, and engineering. Considering that this is a step of evaluation, the percentage of error can be high, almost 20%. The experience of the designer will be very important because his decision can reduce or increase the cost.

b. Operative cost.: With the information obtained on the metallurgical tests can be possible have an operative cost per ton treated. Generally, recycling products and solutions, the consumption can go down. But for evaluation will be considered only the data from laboratory tests.

c. Work capital.: It is the money required to operate the plant until the first production and later generate more incomes.

2.7 Take a decision.: With the information generated in the economic evaluation can be chosen the optimum alternative and the possible options will be studied too. Must be presented a comparison of how will be recovered the capital during the time of life of the project. Thus, investors will take the best alternative; they will have all the tools for calculating the utilities according to the process chosen. Once concluded the election, will be elaborated the final project.