Calculation of the proportions of the oxidants & fluxes versus impurities present in the calcined precipitate

Calculation of the demand for oxygen(kg oxygenates by 100 kg of precipitate)

D.O. = 0.13(%Cu) + 0.29(%Fe) + 0.077(%Pb) + 0.25(%Zn) + 0.5(%S) - 0.18(%MnO2)

The coefficients in red come from the literature

The quantity of MnO2 is function of the experiment and the losses of recovery out of precious metals (max 6-7% in Laronde).

The contents of the impurities are function of the analyses of the calcined precipitate (RASIL02) and their oxidation step (COREM).

Calculation of the demand of Sodium Nitrate

(kg NaNO3 by 100 kg of precipitate) D.O. NaNO3 = [D.O.] x [5.31]

[% effectiveness NaNO3]

% of effectiveness varies according to: the quality of the mixture the temperature heating.

an effectiveness higher than 75% is impossible

Calculation of the demand for silica (kg SiO2 by 100 kg of precipitate)

D.S. = 0.10(%Cu) + 0.26(%Fe) + 0.15(%Pb) + 0.23(%Zn) + 0.17(%MnO2) + 0.35(NaNO3) - 1.0(%SiO2)

The coefficients in red come from the literature

The quantity of SiO2 in the precipitate is withdrawn in calculation

Calculation of the demand for borax (kg borax by 100 kg of precipitate)

D.B. = [0.20(%Cu) + 1.73(%Fe) + 0.39(%Pb) + 1.54(%Zn) + 1.16(%MnO2) + 0.59(NaNO3) + 1.78(%Na2CO3)]

factor mixes

The coefficients in red come from the literature

The quantity of borax can be reduced 10-30% if the power supply of the furnace is well mixed

(factor of mixture = 1 to 1,3)