How are the Earth s elemental reserves explored and calculated?

From a geological point of view, the determination of dispersed elements is ultimately reflected in the degree of verification of the occurrence state of dispersed elements and the accuracy of final reserve calculation, and there are many factors affecting the calculation of reserves, among which the reserve calculation method also has an impact on the accuracy of reserves. For the initial implementation of this work, the key issue is what kind of reserve calculation method to use. There are generally three ways to calculate dispersed element reserves:

First, it is the same as the calculation method of the main element reserves (referring to the calculation method of the reserves of the mining area and the main elements of the mining area), and the grade of the dispersed elements is calculated by arithmetic average or weighted average method.

Compute; The second is the correlation method, which is calculated by statistical methods according to the relationship between the dispersed elements and the main elements by mathematical methods. The most important forms of occurrence of elements on Earth are ions in mineral crystals in various rocks. So study from the whole earth and even the solar system.

To the element content of a grain of mineral, it passes through the bridges of rocks and minerals. Get their chemical composition, and you know the element content. For the whole Earth: Carbonaceous chondrites of type CI are the most primitive of the chemogroups of the various carbonaceous chondrites encyclopedia, which are affected by the atmosphere.

The effect of its volatile element content is small, and its volatile element content is similar to that observed from the sun (spectral analysis.

and other methods) are basically as the elemental abundance of the earth and the sun.

Reference standard (in fact, the abundance of H and He is also somewhat biased). The abundance of non-volatile elements in other carbonaceous chondrites also largely represents the original composition of the solar system. So if you get a few such meteorites, and you know the volume of the earth, you will know the content of the whole earth, and I won't talk about this in detail later.

For the Earth's spheres: Obviously, the elements available to humans are at the surface of the Earth (relative to a radius of more than 6,300 km), that is, the Earth's crust. <>

When delineating the range, it cannot be played casually because of the beauty or your own imagination, and must be in accordance with certain specifications, for example, you need to draw a profile according to the direction of drilling and drilling, and then connect the profile into a volume map; Rock connection lines must be straight; The shape of the rock formation outside the outermost borehole should be inferred to be triangular and the extrapolation distance should be half of the average distance of the borehole; Wait a minute. In addition to facilitating subsequent calculations, the division of ore blocks also has an important role in clarifying the confidence level of the reserves of each ore block. For example, the ore block located in the middle of multiple drill holes has a good guarantee of its boundaries and rock properties, and the calculated reserves will be more accurateOn the other hand, the ore block located on the edge has a large number of inferential components, and the confidence in the calculation of reserves is low.

These are distinguished by strict judging criteria. (It seems that they are proved reserves and speculative reserves respectively, and the technical terms have been forgotten, forgive me.) In block calculation, a simple geometric volume formula, such as a conical or table volume formula, is applied to the corresponding block to obtain its volume, and then the reserves of the block are calculated according to the nature of the rock layer and the confidence level mentioned above.

The formulas used have also been carefully selected. Finally, the reserves of each block are summarized to obtain the total reserves of the deposit. What's the point of such a strict step?

You must know that these steps and results are not for yourself, and their most important role is to report and obtain mineral mining rights. The important basis for the review of the relevant experts in ** is whether these steps and results meet the specifications they identify, if there is a stupid macro in the middle, it will affect the credibility of the entire report, or even fail. The mineral reserves published on ** are the results of the release after ** review and approval.

At the same time, it can be seen that in the process of calculating reserves, there are many measures to simplify the model, which are many years of work experience of geologists on two-dimensional drawings, and after a long-term fact test, they have been recognized by the older generation of experts. These lessons are simple, but effective. However, these provisions have also been challenged by modern technology in Tusan.

One of the tasks of our laboratory is to break the limitations of these plans, profiles or formulas, and directly generate the 3D shape of the ore body from the exploration data, and then directly calculate the volume and reserves based on this 3D model. This practice is not original to us, and there are already foreign miners and software companies who have cooperated to use this practice to calculate reserves;However, the road to reserve reporting based on this method is not yet fully cleared for ** and experts to agree and be able to approve this methodology. <>

For the time being, we understand the reserve calculation as: volume * grade, where the volume is easy to understand, and the entire solid volume is OK;However, the grade calculation is more troublesome, the samples collected here are scattered, and the corresponding grade is also more than one chain, and the taste of the whole mining area can be simply replaced by the average of the metal sample grade dataset p, then the reserve calculation model of this mining area is v*p. The advantage of this calculation is that it is simple and straightforward, but the disadvantage is that the calculation is too simple; Complex mathematical knowledge, blind geologists will not give up on the use.

The current general geological software generally divides the entire ore body into a plurality of suitable unit cells (of course, the size of the unit cell is also said), and the grade value of each unit cell is unique, so the calculation of the entire ore body reserves can be obtained by the sum of these unit cell reserves. So the key now is how to use the mathematical method to calculate the individual unit cell grade size from the existing metal sample grade dataset. It should be noted here that the samples collected are a very small fraction of the ore from the entire mining area.

So the most crucial part is to find the right mathematical method, and there are many ways to do it, such as the inverse ratio of the minimum distance, krieg, etc. <>

The first step in calculating reserves is to determine the "cut-off grade" or "industrial grade", which is the lead mark, and first determine what kind of stone is the ore. In the pre-survey phase, the "cut-off grade" can be determined, while in the "exploration" stage, the "industrial grade" must be used.

Because the "cut-off grade" is the minimum grade value that can be called a mine according to the state, that is, under the most ideal conditions (good mining conditions, good transportation......and other relevant conditions), as long as the grade of the mine is greater than this cut-off grade, you can make money. When it comes to the exploration stage, all aspects of the mine have been evaluated, and it is possible to calculate when the grade of the mine is greater than what value, and then make money. The industrial grade of this industry is different in different regions and different mines.

For example, the cut-off grade of copper is that in a well-developed mine, the industrial grade may be, and in a closed mountainous area, the industrial grade may be 1% (just an example). <

Mineral Reserve Calculations.

mineral reserves，calculation of

Based on the information on the mineral deposits obtained from the geological exploration work, the amount of useful minerals is determined through calculations. This is an important task of mineral exploration, and is the basic basis for estimating the economic value of ore deposits, determining the production scale and service life of mines. The steps for the calculation of the Mineral Reserve are:

Through the cataloguing, sampling and testing of ore outcrops, exploration trenches, shallow wells, tunnels and borehole cores, various geological maps and ore grade, weight and other data required for reserve calculation are obtained. The above-mentioned data are put on the geological map of the corresponding scale according to the three-dimensional spatial coordinate position, and the scope of the ore body is delineated according to the requirements of geological structure and mineralization law and mineral industry indicators. According to the morphology of the ore body and the distribution characteristics of ore quality, considering the distribution pattern of exploration engineering or the layout of the mining field, the ore body is divided into geometric ore blocks of different sizes, and the reserves of each ore block (ore block volume, average ore weight, and average ore grade) are calculated by volume formula, and then summarized into the reserves of the whole ore body and the whole ore deposit.

Mineral reserves are mostly expressed in terms of the amount of useful components or metals, such as several tons of iron, several tons of copper, etc. The above mainly refers to the calculation method of reserves of solid minerals, and the calculation methods and relevant parameters of reserves of liquid (oil, groundwater, etc.) and gas (natural gas) minerals are not all the same.

A lot of new methods for calculating geological reserves of abnormally high-pressure gas reservoirs are not known above, but you said no.