流程考查时选别流程的计算

    由于各个矿山所处理的矿石性质不同，所采用的流程不同，在进行流程计算时采用的计算方法和公式也不相同，现举例说明：
    一、单金属流程的计算

                                                                                                         β₁ - β₂
                                    产率：γ₂ = ————  
                                                                                                         β₂ - β₃

                                                                                                  β₂ （β₁ - β₃）
                                  回收率：ε₂ = ——————
                                              β₁（β₂ - β₃）

                                                                       ε₃ = ε₁ - ε₂  
       
    对于黄金矿山选别流程中的混汞作业和直接提取成品金的重选作业，因为精矿品位与尾矿品位相比差别很大，此时尾矿品位与精矿品位相比可以忽略不计，则β₂-β₃=β₂

                                              β₂（β₁ - β₃）                     β₂（β₁ - β₃）                           β₃
    ∴         ε₂ = ——————100% = ——————100% = 1 -  —— 100%
                                              β₁（β₂ - β₃）                       β₁·β₂                                  β₁

                                                                                                    β₁ - β₃
                                                                  γ₂ = ———— = 0 
                                           β₂ - β₃
      
    ∴                                    γ₃  = γ₁

    在国内的堆浸厂几乎全用上两式计算回收率和产率。[next]
    二、两种属流程的计算
    1.第一种流程的计算

    各产物回收率和产率计算公式：

                                                                          α₁（α - α₂）
                                                               ε_A = ———————
                                                                          α（α ₁- α₂）

                                                                                             b₃（b₁ - b）（b ₂ -  b₄）
                                                          ε_b = ————————————
                                       b（b₁ - b₂）（b₃ - b₄）

                                                                             α - α₂
                                                                  γ_A = —————
                                                                                                       α ₁- α₂

                                                                                         （b₁ - b）（b₂ - b₄）
                                                           γ_B = —————————
                                                                                         （b₁ - b₂）（b₃ - b₄）[next]
    2.第二种流程的计算

    各产物回收率和产率计算公式：

                                                               α₃（α ₁- α）（α₂ - α₄）
                                                    ε_A = ————————————
                                                               α（α ₁- α₂）（α₂ - α₄）
                                                                                        b₄（b₁ - b）（b ₂ -  b₃）
                                                       ε_b = ————————————
                                     b（b₁ - b₂）（b₄ - b₃）

                                                                  （α₁ - α）（α₂ - α₄）
                                                           γ_A = —————————
                                                                                         （α ₁- α₂）（α₂ - α₄）[next]
                                                                                       （b₁ - b）（b₂ - b₃）
                                                       γ_B = ———————————
                                                                                        （b₁ - b₂）（b₄ - b₃）

    以上各式中的ε、γ分别代表各产物中相应的回收率和产率；a、b分别代表各产物中两种不同金属的品位。
    三、单金属三产物流程的计算
    对于单金属三产物流程，在考查计算时，除已知各产物的品位外，还必须知道其中两个产率，才能算出其他产率和各产物的回收率。因此在流程考查前计算出必要而又充分的原始数据后，在分配取样点时必须注意到这一点。当然在闭路流程的计算中，已得出三产物作业前后的有关指标，亦应作为计算三产物流程的原始指标。

    如上图，流程中，β₁，β₂，β₃，β₄，γ₁，γ₂为已知，计算γ₃，γ₄和ε₃，ε₄。
    产率：

                                                                  γ₁β₁ -  γ₂β₂
                                   ———————— - β₄
                                                                     γ₁ - γ₂
                                                      γ₃ = ———————————
                                                                                                  β₃ - β₄
                                                                γ₄ =  γ₁ - γ₂ - γ₃


                                                                    γ₁β₁ -  γ₂β₂
                                                                                 β₃（—————— - β₄）
                                                                                               γ₁ - γ₂
                                                    ε₃ = ———————————
                                                                                           β₁（β₃ - β₄）


                                                                           γ₃β₃
    或                                                         ε₃ = ———
                                                                            γ₁β₁

                                                ε₄ = ε₁ - ε₂ - ε₃ = γ₁β₁ - γ₂ - β₂  - γ₃β₃
  
    以上γ，β，ε等符号意义相同。