WO2018061561A1 - Method for estimating presence of metal compound, method for prospecting metal deposit, method for developing resources, method for mining, method for producing secondary copper sulfide, method for producing resources, method for developing mine, and method for boring - Google Patents

Abstract

This method for estimating the presence of a metal compound is a method for estimating the location and/or the proportion at which a metal compound is present, wherein the method includes observing a reflectance spectrum at an observation site and obtaining an observation value of the reflectance spectrum within a wavelength range of 350-2500 nm, acquiring an observed reflectance spectrum in which the observation value is standardized, and comparing the observed reflectance spectrum with a compound reflectance spectrum of the metal compound.

Description

Presence estimation method of metal compound, exploration method of metal deposit, resource development method, mining method, secondary copper sulfide production method, resource production method, mine development method and boring method

The present invention relates to a method for estimating the existence position and / or proportion of a metal compound, and a metal ore exploration method, resource development method, mining method, secondary copper sulfide production method, resource production method, and mine development using the same. In particular, it proposes a technique that contributes to exploration of metal deposits and other resource exploration, especially by enabling highly accurate and easy estimation of the presence of metal compounds on the ground surface. Is.

In recent years, for example, the consumption of non-ferrous metal resources such as copper and zinc has been increasing. In South America and other regions where resource potential is high but not yet fully explored due to the need to supply resources stably. There is a desire to discover a new metal deposit formed by concentrating metal elements after a long history and to mine from now on.

Such resource exploration and development is costly and time consuming from exploration to mining and the start of resource production. The exploration of metal deposits, which is the initial stage of such exploration, is worthy of such investment. It is desirable to easily find a metal deposit in which metal elements are concentrated at a high concentration with high accuracy.
However, most of the metal deposits are generally underground, especially metal deposits that are shallow from the ground surface have already been explored so far. As deepening is expected, exploration of new metal deposits is becoming increasingly difficult.

Heretofore, surface surveys were conducted to visually observe the surface of the area where metal deposits could be present underground, and chemical analysis of the collected samples was conducted, and based on the experience, etc. Exploration of metal deposits was conducted by drilling at the site and analyzing the components of the substances that make up a range of depths underground. In this case, the rule of thumb and skill is also large, and if there is a misregistration, boring, component analysis, etc. will be performed many times, and there is a problem that costs increase and a lot of time is required.

Under such circumstances, for example, as described in Non-Patent Documents 1 and 2, remote sensing technology for measuring an object remotely by an artificial satellite or an aircraft, or the composition of a substance such as a mineral based on an optical technique With the progress of spectrum analysis technology for estimating the above, such technology has been used also in the exploration field described above.

In Non-Patent Document 1, as a technique used when estimating surface materials of the earth and planets by remote sensing, the relationship between the chemical composition of silicate minerals such as pyroxene and olivine and absorption bands, and various The relationship between the particle size and mixing ratio of various mineral mixtures and the reflection spectrum is discussed.
Non-Patent Document 2 discusses an analysis method that takes into account the particle size and shape in the reflection spectrum of a mixture of minerals using a so-called isoparticle model (Isograin Model).

By the way, it was found that a predetermined metal compound containing metal elements concentrated in the metal deposit is distributed near the surface of the metal deposit.
Information on the distribution of such metal compounds is thought to be very useful for the early detection of metal deposits. However, if the amount of metal compounds present near the surface of the metal deposit is small and the distribution is small, the metal compound It is difficult to confirm the presence of conventional satellite data, and it can be confirmed by field surveys, but it is difficult to accurately grasp changes in its content. The existence of such a metal compound has not been estimated.

An object of the present invention is to cope with such a problem. The object of the present invention is to provide a method for estimating the presence of a metal compound, a metal compound capable of easily estimating the presence of a metal compound, and a metal. It is an object of the present invention to provide an ore deposit exploration method, resource development method, mining method, secondary copper sulfide production method, resource production method, mine development method and boring method.

As described above, the inventor has intensively studied to estimate this under the new knowledge that a predetermined metal compound is distributed near the surface of the metal deposit, and as a result, satellite data or a spectrometer is used. It has been found that by performing a predetermined reflection spectrum analysis, it is possible to easily and accurately estimate the presence of a metal compound.

Based on such knowledge, the presence estimation method of the metal compound of the present invention is a method for estimating the presence position and / or ratio of the metal compound, and the reflection spectrum of the observation point is measured within the wavelength range of 350 nm to 2500 nm. Observing to obtain an observation value of a reflection spectrum, obtaining an observation reflection spectrum obtained by normalizing the observation value, and comparing the observation reflection spectrum with a compound reflection spectrum of the metal compound. .

In the metal compound presence estimation method of the present invention, the wavelength region is 350 nm to 600 nm, 1900 nm to 2500 nm, 900 nm to 2500 nm, 1600 nm to 2500 nm, 350 nm to 600 nm, and 1600 nm to 1600 nm. The thickness is preferably 2500 nm, 500 nm to 600 nm, and 900 nm to 1100 nm.

In the method for estimating the presence of a metal compound of the present invention, it is preferable to estimate the location and / or ratio of the metal compound on the ground surface.
Moreover, in the metal compound presence estimation method of the present invention, it is preferable to estimate the distribution of the presence ratio of the metal compound in the target region.

It is preferable that the method for estimating the presence of a metal compound of the present invention includes calculating a Laplacian indicating a change in an observed reflection spectrum at observation points adjacent to each other.

The above-mentioned metal compound may include one or more selected from the group consisting of goethite, hematite, iron alunite, peacock stone, silicic peacock stone, kyanite, brochantite, atacamaite and gallstone.

In the metal compound presence estimation method of the present invention, it is preferable to compare the observed reflection spectrum with a compound reflection spectrum of a plurality of types of mixed metal compounds.

The method for exploring a metal deposit according to the present invention is the information on the presence or absence of the metal compound containing a metal element contained in the metal deposit in a target region using any one of the above-described methods for estimating the presence of a metal compound. Including obtaining metal compound information including, and estimating the presence of a metal deposit in the target region based at least on the metal compound information.

Here, in the metal deposit exploration method of the present invention, it is preferable that the metal compound information includes information on the distribution of the presence ratio of the metal compound in the target region.

Moreover, it is preferable here that the method for exploring a metal deposit according to the present invention includes obtaining terrain information including information on the level of the ground surface of the target region.
When obtaining this topographic information, it is preferable to estimate the amount of erosion of the ground surface of the target region.
More specifically, the estimation of the erosion amount may be performed by calculating a difference between an actual altitude of the ground surface of the target area and an altitude of the tangent plane, or an altitude of the ridge surface and an actual altitude of the ground surface of the target area. The terrain thickness is calculated from the difference between the terrain thickness, the target area is divided into a plurality of zones according to the thickness of the terrain thickness, and a coefficient of a size according to the thickness of the terrain thickness is given to each zone. It can include obtaining a distribution. This altitude means the height of the ground surface, the valley face or the ridge face from a predetermined reference plane. Among these, the altitude of the ground surface can be set to an altitude based on the sea surface, and in this case, the altitude of the tangent surface and the ridge surface is the height from the sea surface as a predetermined reference surface.
Here, it is preferable to set the length of one side of the square grid that divides the target area when obtaining the tangent face or the ridge face within a range of 1000 m to 2000 m.

The resource development method of the present invention includes any one of the above-described metal deposit exploration methods.
The mining method of the present invention is to perform mining in the target region where the presence of the metal deposit is estimated by any one of the above-described metal deposit exploration methods.
The method for producing secondary copper sulfide according to the present invention is to produce secondary copper sulfide in the target region in which the presence of the metal deposit is estimated by any one of the above-described metal deposit exploration methods.
The resource producing method according to the present invention produces resources in the target area in which the existence of the metal deposit is estimated by any one of the above-described metal deposit exploration methods.
The mine development method of the present invention is to develop a mine in the target region where the existence of the metal deposit is estimated by any one of the above-described metal deposit exploration methods.
The boring method of the present invention is to perform boring in the target region in which the existence of the metal deposit is estimated by any one of the above-described metal deposit exploration methods. Here, during the excavation by the boring, it is preferable to measure the reflection spectrum of the material constituting the hole wall of the boring and determine the excavation length of the boring point based on the measurement result of the reflection spectrum.

According to the metal compound estimation method of the present invention, the presence position and / or the presence ratio of the metal compound can be easily estimated with high accuracy by performing the reflection spectrum analysis as described above.
Therefore, when this metal compound estimation method is used for exploration of metal deposits and other resource exploration, it can contribute to reduction of time and cost required for such exploration.

It is a graph which shows the reflection spectrum characteristic of a predetermined substance. It is a schematic sectional drawing in the depth direction of an underground showing the mineralization process of a metal deposit. It is a graph which illustrates the method of setting the coefficient of four steps according to terrain thickness. It is satellite data which shows the MantoVerde deposit of an Example. It is a figure which shows the result of having performed the reflection spectrum analysis with respect to the satellite data of FIG.

Hereinafter, embodiments of the present invention will be described in detail.

<Presence estimation method of metal compound>
In the method for estimating the presence of a metal compound according to an embodiment of the present invention, the reflection spectrum at an observation point is observed in the wavelength region of 350 nm to 2500 nm when estimating the location and / or ratio of the metal compound. Obtaining the observed value of the reflection spectrum, normalizing the observed value to obtain the observed reflection spectrum, and comparing the observed reflection spectrum with the compound reflection spectrum of the metal compound.

(Metal compound)
The metal compound can be, for example, a combination of a metal element contained in a metal deposit, which will be described later, and other elements. Specifically, goethite, hematite, iron alunite, peacock stone, siliceous peacock stone And one or more selected from the group consisting of kyanite, brochantite, atacamaite, and gallstone. Among these, peacock stones and silicic peacock stones are more preferable because they are more easily formed than other copper minerals and have a large amount of distribution on the surface of the earth.

The metal element contained in the metal compound preferably contains one or more selected from the group consisting of copper, molybdenum, iron, tin, tungsten, gold, silver, lead and zinc.
In particular, when the metal element contained in the metal compound is copper, the metal compound preferably contains one or more selected from the group consisting of peacock stone, silica peacock stone, kyanite, brochantite, atacamaite, and gallstone. It is.

In one embodiment of the present invention, at least one of the existence position and the existence ratio of the metal compound as described above, preferably the distribution of the existence ratio, is estimated in a predetermined target region. Perform spectral analysis.

(Reflection spectrum analysis)
By using reflection spectrum analysis to estimate the presence of metal compounds, differences in results due to individual differences can be suppressed compared to visual confirmation, and compared to component analysis using X-ray diffractometry. Thus, it can be performed over a wide range at low cost and in a short time.

In reflection spectrum analysis, for example, satellite data or a spectrometer (spectrometer) is used to observe the reflection spectrum of the ground surface, such as the ground surface or rock surface, in the target area, and obtain the observation value of the reflection spectrum. Are subjected to various mathematical treatments to calculate the existence position and / or the existence ratio of the metal compound on the ground surface of the target region. The ground surface is an exposed surface, and it is considered that light can enter optically as long as the depth is about 1 cm from the ground surface.
The spectrometer is mounted on a manned or unmanned aircraft flying over the target area, or a manned or unmanned vehicle or other vehicle moving on the ground surface of the target area, or may not move on the ground surface of the target area. It can be used by being held by a walking observer.

Specific examples of the data that can be used here include, for example, data based on ASTER, WorldView-2, WorldView-3, AITRES, airborne HyMap sensor, AVRIS, and the like. Examples include, for example, ARCspector Rocket manufactured by AROptix, Fieldspec manufactured by ASD, and the like. Further, data of hyperspectral satellites to be launched in the future (for example, EnMap (Germany), PRISMA (France), HISUI (Japan), etc.) can also be used.
In particular, the spatial resolution is preferably about several meters and the wavelength resolution is about 10 nm, and the quantization is preferably 1000 gradations or more (10 to 12 bits). As a result, even if the distribution of metal compounds on the ground surface is small and small, it can be effectively observed. As the number of gradations increases, a slight change can be identified, so that the detection limit value decreases.

An example of a reflection spectrum analysis method is as follows. First, by using satellite data or measuring with a spectrometer, the ground surface and rocks of one or more observation points in the target region within the wavelength range of 350 nm to 2500 nm. A reflection spectrum of the surface or the like is observed, and an observation value of the reflection spectrum at the point is obtained. Here, necessary corrections such as atmospheric correction can be performed by a known method.

Next, the observed value of the reflection spectrum is normalized (unit vectorized) to obtain the observed reflection spectrum. More specifically, normalization of the observed reflection spectrum should be performed by dividing each observation value by a predetermined reference observation value under the same conditions or the square root of the sum of squares of each value of the observation value. Can do. The reason for this standardization is as follows. The observed value is the amount of light incident on the sensor (absolute value). That is, in the satellite data, the sunlight, shade, solar altitude, atmospheric transparency, and the like change, so that the amount of incident light on the sensor that is observed differs even with the same substance. Similarly, in the case of a measuring device, the amount of incident light varies depending on the aging of the light source, the distance from the object, and the like. Since it is difficult to estimate a substance with such an incident light quantity, the above-described normalization is performed.

The observed reflection spectrum thus obtained is compared with the compound reflection spectrum of a predetermined metal compound. The compound reflection spectrum to be compared is known or can be obtained by separate measurement. According to the similarity by this comparison, the existence position or the existence ratio of the metal compound can be estimated.

In order to measure the degree of similarity, for example, a spectral angle mapper (SAM) method, a cross-correlation method, or the like can be used. The SAM method is expressed as an n-dimensional vector corresponding to the number of bands, and the material of the metal compound forming the minimum angle with this is output as a solution. The cross-correlation method is based on the correlation coefficient between reflection spectra. In this method, the substance of the metal compound having the highest correlation coefficient is used as a solution, and these methods are already known in the art.
Alternatively, it is also possible to compare with the compound reflection spectrum of a metal compound in which multiple types of metal compounds are mixed instead of a single mineral, and a model for accurately determining the constituent ratio from the compound reflection spectrum of such a mixture As the above-mentioned equi-particle model.

Here, the metal compound has different reflection spectrum characteristics depending on its type. As a specific example, FIG. 1 shows the reflection spectrum characteristics of plants, gallstones, silicic peacock stone, brochant copper ore and atacama stone. For example, it can be seen from FIG. 1 that these minerals exhibit reflection spectral characteristics different from those of plants, generally in the visible region and the short-wavelength infrared region.

An appropriate wavelength region can be set according to the reflection spectral characteristics of each substance.
From the results shown in FIG. 1, when estimating the distribution of the existence ratio of gallstones, silicic sphalerite, brochantite, atacamaite, etc., the wavelength range is 350 nm to 600 nm, 1600 nm to 2500 nm, especially 1900 nm in order to estimate with high accuracy It can be said that setting to ˜2500 nm is preferable. For kaolin, sericite, and alunite, the wavelength range of 2000 nm to 2500 nm is particularly effective. The wavelength region can also be set to 900 nm to 2500 nm.
Alternatively, when estimating the distribution of the abundance ratio of goethite, hematite, etc., it is preferable to set the wavelength ranges of 500 nm to 600 nm and 900 nm to 1100 nm, which are characteristic of the reflection spectrum characteristics of these minerals. In addition, when using a spectrometer, it is preferable to set to 1300 nm to 1600 nm. In satellite data, this range may not be observable due to atmospheric absorption (water vapor, etc.).

By performing the above-described method for all zones in which the target area is partitioned by mesh, a map of the distribution of the presence ratio of the metal compound in the target area can be created.

Here, the distribution of the presence ratio of the metal compound can be evaluated by a Laplacian that represents a change in data at three consecutive points.
As the form of change of data at three consecutive points, (1) When the inclination of two adjacent points does not change (regardless of the inclination of the three points horizontal, right-up, or right-down, the change is linear) (2) When the inclination of two adjacent points becomes large (when the inclination of two points after the first two points is large), (3) When the inclination of two adjacent points becomes small ( The slope of the two points after the first two points is small). Here, if each of the three consecutive points of data is A, B, and C and defined as Laplacian = (2 × B) / (A + C), in the case of (1) above, B at the midpoint is A and C Laplacian = 1.0, and in the case of (2) above, the intermediate point B is below the straight line connecting A and C, and Laplacian <1.0. In the case of (3), the intermediate point B is above the straight line connecting A and C, and Laplacian> 1.0. If a substance with strong B reflection is added to (1) above, it is expected to change to (3) above. In order to detect the presence or absence of such a substance having a reflection peak at B, it can be evaluated by Laplacian. This method using Laplacian is effective in that it can be carried out more easily than the method using the above-mentioned equivalent particle model.

By the way, the observed value of the reflection spectrum described above can be multispectral data obtained by observing only a specific wavelength. For example, the wavelength range from visible to short-wavelength infrared region such as 400 nm to 2500 nm is continuous. From the viewpoint of improving accuracy, it is preferable to obtain continuous spectrum data obtained by measurement. Continuous spectrum data can be obtained by using hyper data, measuring with a portable reflection spectrum measuring device, or the like. Specifically, as hyperdata, among the data used in the above-described reflection spectrum analysis, there are data by airborne HyMap sensor, AVRIS, AITRES, EnMap, PRISMA, HISUI, etc., and a portable reflection spectrum measuring instrument. For example, there is an ARCspector Rocket manufactured by AROptix Corporation, a Fieldspec manufactured by ASD Corporation, and the like.

<Exploration method of metal deposit>
The metal compound existence estimation method using the reflection spectrum analysis described above can be used for exploration of metal deposits.
That is, in the exploration of the metal deposit according to one embodiment of the present invention, the presence / absence of the metal compound containing the metal element contained in the metal deposit in the target region is determined using the above-described method for estimating the presence of the metal compound. And obtaining information on the metal compound including the information on, and inferring the existence of the metal deposit in the target area based at least on the metal compound information.
Here, “including” predetermined information includes not only the predetermined information and one or more pieces of information other than the predetermined information, but also includes only the predetermined information. Shall.

(Metal deposit)
Although this method can be used for exploration of various metal deposits, as understood from the theory based on the mineralization process described later, in particular, high-temperature groundwater due to magma reacts with surrounding rocks, and metal components, etc. It is suitable for exploration of hydrothermal deposits formed by precipitation, especially porphyry copper deposits. In addition, IOCG type deposits (iron oxide type copper gold deposits), skarn deposits, epithermal water type deposits, etc. can be effectively applied because they involve alteration and Cu mineralization.

Metal deposits such as hydrothermal deposits, including the block rock copper deposit, are formed through two mineralization processes: primary mineralization and secondary enrichment.
In the primary mineralization, as shown in Fig. 2 (a), the underground water of the stratified volcano 1 and so on is affected by the hot water 2 released from the deep underground as the magma rises. A primary mineralized zone 3 containing primary copper sulfide and the like is formed at a deep location. At this time, the hot water and the rock react to generate an alteration zone 4 containing alteration minerals such as biotite, sericite and chlorite around the primary mineralization zone.

After that, with the passage of millions to tens of millions of years, as shown in Fig. 2 (b), uplift and erosion occurred, and the primary mineralized zone 3 approached the surface side, and the vicinity of the surface In the leaching zone 5, the primary copper sulfide is leached by the acid formed by the decomposition of pyrite by rain RF and the like, and the secondary enriched zone 6 is formed by depositing secondary copper sulfide and the like under the groundwater surface GL. Secondary mineralization occurs. The secondary enrichment zone 6 as a whole moves downward due to surface erosion and groundwater level reduction, and grows as copper leached in the leaching zone 5 moves downward from the leaching zone 5. Even after the secondary enrichment zone 6 is formed, the alteration zone 4 containing alteration minerals generated by the primary mineralization is present around or in the vicinity thereof. In the leaching zone 5, alteration minerals (kaolin, iron alumite, etc.) formed along with leaching are also present.

And in the metal deposit formed by such a mineralization process, the new knowledge that such a metal compound may be distributed in small quantities and small scales near the ground surface was acquired.
Therefore, it is considered that the metal compound information obtained by the above-described method for estimating the presence of the metal compound is used for exploration of the metal deposit, leading to early discovery of the metal deposit.

(Terrain information)
In the exploration of a metal deposit, in addition to using only the above metal compound information, it is also possible to use the metal compound information in combination with terrain information including information on the height of the ground surface of the target region.
In areas where the altitude is relatively high, such as mountains and ridges, the thickness of the leaching zone 5 is sufficient, so that secondary copper enriches and descends primary copper sulfide, etc., resulting in secondary enrichment underground. Grow strip 6. On the other hand, in relatively depressed areas such as valleys, the erosion of the ground surface is fast, and a substantial amount of primary copper sulfide is removed along with the erosion. It is thought that enrichment zone 6 did not grow. In other words, it is considered that in the mountains, ridges, and the like, the effective leaching thickness was thick because erosion was slow and the time required for leaching was sufficiently secured, so that the secondary enriched zone 6 was likely to grow. Therefore, secondary copper sulfide accumulation due to secondary enrichment is considered to be strongly controlled by the current topography, indicating that topography is important information for exploration of metal deposits.

From such knowledge, it is preferable that the estimation of the formation process of the secondary enrichment zone includes information on the level of the ground surface of the target region, more specifically, information on the amount of erosion of the ground surface of the target region.
When estimating the amount of erosion on the ground surface of the target area, the difference between the actual height of the ground surface of the target area and the height of the close contact surface, which is an approximate surface of the groundwater surface, or an approximation of the past topographic surface The terrain thickness is calculated from the difference between the altitude of the ridge face that is the surface and the actual altitude of the ground surface of the target area, and the target area is divided into multiple zones according to the thickness of the terrain thickness. Can be obtained by obtaining a terrain thickness distribution to which a coefficient corresponding to the thickness of the terrain thickness is given. More details are as follows.

The tangent surface and the ridge surface are virtual surfaces that can be used for groundwater level estimation, topographic analysis, etc., and divide the target area with a square grid of a predetermined size and touch the lowest point in each grid Such a surface is a tangent surface, and a surface that is in contact with the highest point in each grid is a tangential surface. Here, the summit and ridges are considered to have escaped erosion, and the valleys are considered to have been greatly eroded.
In this case, the length of one side of the square grid is preferably set within a range of 1000 m to 2000 m. The reason is that the interval between the large valleys carving the slope takes this value. In other words, if the length of one side of the square grid is less than 1000 m, the mesh will be cut at an interval narrower than the valley interval, and the highest elevation will be obtained between the valleys. If the length of one side of the square grid is larger than 2000 m, it will be a point from two or more large valleys, and the surface that touches the current terrain It may not be possible. The mesh size needs to be changed depending on the terrain (rock) and the erosion stage, and is preferably determined in consideration of the terrain characteristics of the region (mainly the wavelength of the valley).

Next, the difference (absolute value) between the altitude of any one of these tangent faces or ridge faces and the actual altitude of the ground surface is calculated, and this is used as the terrain thickness.
If the difference between the altitude of the contact surface and the actual ground surface is defined as the terrain thickness, the thinner the terrain thickness, the greater the erosion rate and the faster the erosion rate.

After that, the target area is divided into a plurality of zones according to the thickness of the topography thickness, and a coefficient of a size according to the thickness of the topography thickness is given to each zone, so that the topography thickness distribution Get. For example, as shown in FIG. 3, a factor of 1.00 is given to a zone where the terrain thickness is thicker than 300 m, and a factor of 0.75 is given to a zone where the terrain thickness is 200 m to 300 m. A zone of 100m to 200m can be given a coefficient of 0.50, and a zone of less than 100m can be given a coefficient of 0.25. Zones with thicker terrain, that is, zones with a higher coefficient are considered to have lower erosion rates. Based on the knowledge of secondary enrichment described above, such zones are secondary enriched underground. There is a high possibility that the band 6 has grown greatly and there is an effective metal deposit.

Of course, the coefficient given by each terrain thickness is not limited to the above-described value, and can be set as appropriate.
Also, here, there are four levels according to the thickness of the terrain, and each coefficient is given to these. Since the terrain thickness is meaningless and has no precision even if it is subdivided, it can be divided into four levels. It is preferable to classify in 10 stages. In particular, 4 steps, 5 steps or 10 steps, and 4 steps or 5 steps, which are not fractional, are more preferable.

Also, here, the terrain thickness is divided every 100 m, and the range of terrain thickness that gives the same coefficient is 100 m. The range of terrain thickness that gives the same coefficient is basically the maximum value of the thickness. Although it can be set to a value divided by the number of divisions described above, it can be adjusted so that the maximum value of the thickness is divided and divided when the value cannot be divided.

(Estimation of metal deposits)
As described above, after acquiring the metal compound information and, in some cases, also acquiring the topographic information, the presence of the metal deposit in the target area based on at least the metal compound information, preferably the metal compound information and the topographic information. Infer.

The presence of metal compounds on the surface is an indicator that suggests the presence or absence of mineralization. That is, the metal compound information suggests the possibility that a predetermined metal deposit exists in the vicinity of the metal compound on the ground surface. Therefore, the metal compound information can be one of effective judgment materials for estimating the deposit.
In addition, exploration using a combination of topographical information that indicates the size of leaching thickness also takes into account the size of the secondary enrichment zone that has grown by secondary mineralization. This is preferable because the possibility of discovery is further increased.

In estimating the presence of metal deposits in this way, the distribution of the presence ratio of the metal compound in the metal compound information, the topography thickness distribution in the topography information, and the distribution of the presence ratio of the metal compound are multiplied by the topography thickness distribution. Can be mapped on a map, so that it can be easily grasped visually.

<Resource development>
As described above, after exploring a metal deposit, resource development can be performed based on the exploration results. More specifically, it is possible to conduct drilling and mining in the predetermined target area where the existence of the metal deposit is estimated by the exploration method of the metal deposit, to produce resources such as secondary copper sulfide, and to develop the mine. it can. This boring is an operation in which a cylindrical hole such as a cylinder is excavated in the ground, and a sample in the depth direction such as a core can be taken at that time, and is sometimes referred to as a borehole. . Boring is widely used in geological surveys and underground resource collection, and various boring methods including known or well-known boring methods can be employed in the present invention. In this specification, “exploration” is a concept including searching for a metal deposit. The “resource” is a concept including an object containing metal elements, ore or mineral. “Resource development” is a concept that includes mining resources and / or producing resources and / or making resources available. “Developing a mine” is a concept including making a mine.

When drilling, by measuring the reflection spectrum of the material that constitutes the hole wall around the boring during drilling, how much depth is to be drilled from the measurement result of the reflection spectrum. You can determine the digging length about.
For example, at a predetermined depth position, the alteration intensity of kaolin (T_Kao / T_Clay) represented by the ratio of the concentration of kaolin to the total concentration of altered minerals is calculated from the measured reflection spectrum, and the T_Kao / T_Cray is still high. For example, it is considered necessary to dig deeper. On the other hand, if T_Kao / T_Cray becomes sufficiently low, it is considered that boring has been carried out to a depth position that has passed through the secondary enrichment zone, and it is judged that no good part will come out even if drilling further. Can do.
In the initial exploration stage, there may be several hundred meters of leaching section in the ridge. Even in such places, if T_Kao / T_Clay is high, a good secondary enrichment zone can be distributed deeper.

Next, the present invention was implemented on a trial basis and the effects thereof were confirmed and will be described below. However, the description here is for illustrative purposes only and is not intended to be limiting.

The distribution of the content of metal compounds containing copper (so-called copper oxide) was estimated for the MantoVerde deposit (IOCG type deposit) in Chile as shown in FIG. The satellite data used for this estimation was WorldView-2, which is high-space / high-wavelength-resolution satellite data, and 400-600 nm (blue to green wavelength) where the reflection peak of the metal compound is present was analyzed with priority. The result is shown in FIG.

From the results shown in FIG. 5, it was possible to detect even in a zone where the content of the metal compound was extremely small.
Therefore, it has been found that there is a possibility that such metal compound information can be effectively used for the exploration method of the metal deposit.

1 Stratified volcano 2 Hot water 3 Primary mineralized zone 4 Alteration zone 5 Leaching zone 6 Secondary enrichment zone RF Rainfall GL Groundwater surface

Claims (25)

1. A method for estimating an existing position and / or an existing ratio of a metal compound,
   In the wavelength region of 350 nm to 2500 nm, the observation spectrum of the observation point is observed to obtain an observation value of the reflection spectrum, the observation reflection spectrum obtained by standardizing the observation value, and the observation reflection spectrum, A method for estimating the presence of a metal compound, comprising comparing with a compound reflection spectrum of the metal compound.
2. 2. The method for estimating the presence of a metal compound according to claim 1, wherein the wavelength region is 350 nm to 600 nm.
3. 2. The method for estimating the presence of a metal compound according to claim 1, wherein the wavelength region is 1900 nm to 2500 nm.
4. 2. The method for estimating the presence of a metal compound according to claim 1, wherein the wavelength region is set to 900 nm to 2500 nm.
5. 2. The method for estimating the presence of a metal compound according to claim 1, wherein the wavelength region is 1600 nm to 2500 nm.
6. 2. The method for estimating the presence of a metal compound according to claim 1, wherein the wavelength region is 350 nm to 600 nm and 1600 nm to 2500 nm.
7. 2. The method for estimating the presence of a metal compound according to claim 1, wherein the wavelength region is 500 nm to 600 nm and 900 nm to 1100 nm.
8. The method for estimating the presence of a metal compound according to any one of claims 1 to 7, wherein the presence position and / or ratio of the metal compound on the ground surface is estimated.
9. The method for estimating the presence of a metal compound according to any one of claims 1 to 8, wherein the distribution of the presence ratio of the metal compound is estimated in the target region.
10. The method for estimating the presence of a metal compound according to any one of claims 1 to 9, comprising calculating a Laplacian indicating a change in an observed reflection spectrum at observation points adjacent to each other.
11. The metal compound includes one or more selected from the group consisting of goethite, hematite, iron alunite, peacock stone, silicic peacock stone, kyanite, brochantite, atacamaite and gallstone. The presence estimation method of the metal compound as described in any one of these.
12. The method for estimating the presence of a metal compound according to any one of claims 1 to 11, wherein the observed reflection spectrum is compared with a compound reflection spectrum of a plurality of types of mixed metal compounds.
13. A method for exploring metal deposits,
    Using the method for estimating the presence of a metal compound according to any one of claims 1 to 12, information on the presence or absence of the metal compound containing a metal element contained in the metal deposit in a target region is included. Obtaining metal compound information,
    A method for exploring a metal deposit, comprising estimating the presence of a metal deposit in a target area based at least on the metal compound information.
14. The method for exploring a metal deposit according to claim 13, wherein the metal compound information includes information related to a distribution of a presence ratio of the metal compound in the target region.
15. The method for exploring a metal deposit according to claim 13 or 14, comprising obtaining terrain information including information related to the level of the ground surface of the target region.
16. The method for exploring a metal deposit according to claim 15, wherein when the topographic information is obtained, an amount of erosion of the ground surface of the target region is estimated.
17. The estimation of the erosion amount is based on the difference between the actual altitude of the ground surface of the target area and the altitude of the tangent surface, or the difference between the altitude of the ridge surface and the actual altitude of the ground surface of the target area. And calculating a terrain thickness distribution in which a target area is divided into a plurality of zones according to the thickness of the terrain thickness, and a coefficient of a size according to the thickness of the terrain thickness is given to each zone. The method for exploring a metal deposit according to claim 16.
18. 18. The method for exploring a metal deposit according to claim 17, wherein the length of one side of the square grid that divides the target area when determining the tangent face or the ridge face is set within a range of 1000 m to 2000 m.
19. A resource development method including the exploration method for a metal deposit according to any one of claims 13 to 18.
20. A mining method in which mining is performed in the target region in which the presence of the metal deposit is estimated by the metal deposit exploration method according to any one of claims 13 to 18.
21. A method for producing secondary copper sulfide, wherein secondary copper sulfide is produced in the target region in which the presence of the metal deposit is estimated by the metal deposit exploration method according to any one of claims 13 to 18.
22. 19. A resource production method for producing resources in the target area in which the presence of a metal deposit is estimated by the metal deposit exploration method according to any one of claims 13 to 18.
23. A mine development method for developing a mine in the target area in which the existence of a metal deposit is estimated by the metal deposit exploration method according to any one of claims 13 to 18.
24. A boring method in which boring is performed in the target region in which the presence of a metal deposit is estimated by the metal deposit exploration method according to any one of claims 13 to 18.
25. The boring according to claim 24, wherein during the drilling by the boring, a reflection spectrum of a material constituting a hole wall of the boring is measured, and an excavation length of the boring point is determined based on a measurement result of the reflection spectrum. Method.

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