A very important part of any open-pit mining project is determining the ultimate pit limits and optimizing the pushbacks. Currently, block models are the most widely used for calculating mineral resources and reserves. Block models can define the ultimate pit limits through algorithms like floating cone, Lerchs-Grossmann, PseudoFlow, etc. However, only through an economic study will the best pits be selected, from most to least economically valuable, and the different possible pushbacks can then be defined.

Based on pre-determined operating costs, all possible scenarios should be studied while varying the selling price in fixed increments between minimum and maximum values that cover all possible future prices. The starting selling price should be very low, and consequently, the only phase that will be economical is the one with adequate grade and a low stripping ratio. As the selling price increases, the ultimate pit limits do not vary or vary only slightly until the price reaches the point at which another of the ore bodies in the deposit becomes economical. This process is repeated as the price increases until the maximum price considered is reached; then, the project reaches the last phase that is economical if economic conditions are very favourable.

The data obtained in each phase can be used to simulate different scenarios, since the different phases will not change because operating costs or economic conditions change. The ore is not going to move; what changes is the phase up to which mining will be economical and what profits will be obtained in each phase.

任何露天采矿项目的一个非常重要的部分是确定最终的采矿极限并优化后推力。当前，块模型是最广泛用于计算矿产资源和储量的模型。块模型可以通过浮动圆锥，Lerchs-Grossmann，PseudoFlow等算法定义最终的坑极限。但是，只有通过经济研究，才可以选择最佳坑，从经济价值最高的到最不经济的，然后可以进行各种可能的后推被定义。

根据预定的运营成本，应研究所有可能的方案，同时以最小增量和最大值之间的固定增量更改销售价格，以覆盖所有可能的未来价格。起始销售价格应该非常低，因此，唯一经济的阶段就是具有足够等级和低剥离率的阶段。随着售价的增加，最终矿坑极限不会变化或仅略有变化，直到价格达到矿床中另一个矿体变得经济的地步。价格上涨时重复此过程，直到达到所考虑的最高价格为止；然后，如果经济条件非常有利，则该项目将进入经济的最后阶段。

每个阶段获得的数据可用于模拟不同的场景，因为不同的阶段不会改变，因为运营成本或经济条件会发生变化。矿石不会移动。什么变化是在哪个阶段进行经济开采以及每个阶段将获得什么利润。