For the evaluation of mineral deposits and provide relevant technical data required for plant design, to take core samples representative in deposits for different scale beneficiation tests.
The representative ore sample used in the ore dressing test means that the sample can fully reflect the extent of the existing exploration level of the deposit (optional test sample means full ore ore; process, semi-industrial and industrial beneficiation test sample) Represents the physical, chemical, mechanical properties and quantitative relationship of various ore types in the ores mined during mining or in the early years of mining.
For representative mineral samples, the conditions for sampling control should be fully grasped and discussed with relevant departments such as exploration, design and production. Study the characteristics of ore and its possible influence on the beneficiation method, process flow, selection index and the reliability, existing problems and solutions of sampling conditions. On this basis, carefully prepare the sampling design, correct construction, proper packaging and management.
I. Mineral processing test requirements for mineral samples
According to the purpose of the ore dressing test, in addition to the general requirements for the ore sample, there are special requirements for the optional test and the ore sample for the ore dressing process test.
(1) General requirements
1. The ore sample should reflect the industrial grade and proportion, natural type and proportion of the ore within a certain range of the whole deposit or deposit; mineral composition, structural structure, particle size embedding characteristics; physical and mechanical properties of the ore.
2. The average grades of all grades and types of minerals (including beneficial, harmful and comprehensively recoverable elements) and grade fluctuation characteristics* should be consistent with the grades within the corresponding range of the deposit, and the average grade and grade fluctuation characteristics of each type of ore are basically Consistent.
3. At the same time as the mining sample, a certain amount of ore body surrounding rock and stone sample should be taken. The quantity: when there is mining design, it should be determined according to the waste rock mixing rate provided by the mining design; when there is no mining design, generally the ore body has open-pit mining conditions, and the total amount of stone and surrounding rock sample is the total sample. 5~10% of the amount; when the ore body needs underground mining, the total amount of stone and surrounding rock is 10~25% of the total weight of the ore sample. In special cases (such as thin ore, interlayer or fine vein deposit) Etc.) The number of surrounding rock samples of the stone shall be determined according to the specific conditions. The type and proportion of the stone and surrounding rock to be taken shall be similar to the actual conditions mixed into the ore during mining in the corresponding range of the deposit.
4. When the surrounding rock of the near mine or the inclusion in the ore body is found to have the recovery value, the representative state should be taken in detail to study the comprehensive recovery.
(2) Special requirements
1. Special requirements for optional test ore samples
(1) Where there is a certain proportion of various natural types of ore in the deposit (the type of ore classified according to the mineral co-formation or component content), it shall be sampled separately in order to determine the industrial utilization value of the ore by experiment.
(2) To determine a reasonable cutoff grade, low grade shall be taken individually representative ore samples system (e.g., magnetic iron ore can TFe <20% grade sampling points).
2. Special requirements for ore samples for mineral processing
(1) When the grades or ore types in different mining stages vary greatly, representative ore samples shall be taken according to different mining stages divided by the mining design to conduct separate tests.
(2) Sometimes, in order to obtain the beneficiation index within a few years before the mining, a representative ore sample should be taken for the ore in the early stage of mining.
(3) General requirements for the weight of the sample
The weight of the sample is usually determined by the scale of the test, the processing capacity of the equipment and the content of the test. The weight of the ore sample required for different test scales can be referred to Table 1.
In addition to the various sample tests listed in Table 1 for the weight of the ore sample required for different ore types, the weight of the ore sample should be increased during certain special tests. For the shaft furnace roasting test, the weight of the required ore sample should be increased by 300~500 kg compared with the laboratory test. If the large particle size (75~10 mm) dry magnetic separation test and the heavy medium vibration chute test are carried out. The weight of the ore sample is 2000~3000 kg.
Ore Beneficiation of ferrous metals ore desired weight (kg) Table 1
Ore type | Optional test ore sample | Laboratory sample test sample amount | Semi-industrial and industrial test ore samples |
Magnetite Hematite ore, siderite or easy-to-select polymetallic iron ore Difficult choice of polymetallic iron ore Yi is selected from manganese ore Difficult manganese ore Chrome ore | 100~200 200~300 300~500 100~300 300~500 100~300 | 200~400 300~1000 500~3000 300~500 500~1000 300~500 | The weight of the ore sample depends on the processing capacity of the equipment used in the test and the necessary test time. |
Second, the preparation of the necessary technical information for sampling design
(1) Relevant technical information on deposit exploration
1. The shape, spatial distribution and proportion of ore bodies within a certain range of the whole deposit or deposit.
2. The natural type of ore, the degree of oxidation and the division of industrial grades and their dependence on mineral composition and chemical composition.
3. The relationship between the natural type of ore and the average grade, grade fluctuation characteristics and quantity ratio of industrial grade.
4. The existence, spatial distribution and quantity of beneficial, harmful components and elements that can be comprehensively recovered.
5. The structure of the ore, the size of the mineral inlay and the physical mechanism.
6. The angle of the ore body, the surrounding rock and the type of stone and its chemical composition and quantity ratio.
(2) Relevant technical information on mining
1. The mining or mixed mining conditions of various types and grades of ore, as well as the technical requirements of users for ore mining.
2. The proportion and average grade of ore of each type and grade of ore in different mining periods.
3. The mixing rate of various rocks during the mining process or the range of depletion of each rock mass.
4. User requirements for ore and concentrate quality.
Third, the preparation of sampling design
(1) Determine the number of samples
The sampling design is first determined on the number of samples. The general principles are as follows:
1. If the ore type, industrial grade and associated beneficial, harmful components and comprehensive recycling components have great influence on the beneficiation method, process flow and mineral processing index, they should be sampled separately, otherwise a mixed sample may be taken. For example, iron ore is of a single type with similar composition, and a mixed sample can be taken. Another example is quartz -type magnetite and amphibole-type magnetite. The former is a non-silicate type, and the latter is an iron silicate type. The two have different influences on the selection index and can be separately sampled. For example, there are two kinds of high-sulfur ore and low-sulfur ore in iron ore. The cobalt in high-sulfur ore has reached the comprehensive recycling requirement and should be sampled separately.
2. Separately mined deposits should be sampled separately
3. When a certain amount of off-balance sheet ore is contained in the deposit, the off-balance sheet sample should be taken separately.
4. The user's various requirements for the mining should be considered.
Although the ore has the necessity of separate sampling, sometimes it is determined by the natural type of ore, the spatial distribution of each industrial grade, the mining method, the mining technical conditions, etc., and when the ore is not mined, the mixed sample is taken.
(2) Factors that need to be controlled by sampling
1. Factors that need to be controlled in mining stone samples
After the number of samples is determined, the factors that need to be controlled by sampling can be summarized according to the different characteristics of the ore in the same sample and the possible effects on the test, which are illustrated in the form of FIG.
(1) If the ore sample is collected from several ore bodies, each ore body shall be controlled in the form of this figure.
(2) 20~23; 23~26... in Fig. 1 indicates the grade area delineated by TFe, the purpose of which is to reflect the fluctuation characteristics of the grade and control some structural characteristics. For example, block-like structures, densely disseminated to sparsely disseminated structures correspond to ore grades from rich to poor, so control grades can also control certain ore structures. And some deposits are from block to sparsely disseminated ore, the grain size is from coarse to fine, and the grade can reflect the grain size characteristics.
[next] (3) The factors determining the size of the grade area are:
1) Grade fluctuation characteristics. In order to correctly reflect the fluctuation characteristics of the ore grade, the smaller the grade interval, the better.
2) When there are certain characteristics of the ore and the grade, it is appropriate to use between the cells. Otherwise the interval can be slightly larger.
If the grade interval of the iron ore is TFe1~5%, it can meet the requirements.
2. The factors that need to be controlled when mining rock samples.
When mining samples, it is necessary to use depleted rock samples. The factors that need to be controlled for this sample are listed in Figure 2.
(3) Calculation of sampling grade, weight percentage and weight
1. Ore-like
(1) When there is mining design, each ore body, the type of ore produced and the proportion of mined ore determined by the mining design are used as the relevant grades and proportions in the sampling design.
(2) In the case of no mining design, firstly, the relevant data in a certain range obtained in geological exploration shall be grouped according to Figure 1, and then the sampling grade, weight percentage and weight of each group shall be calculated according to the following formula.
1) Average grade
Where βcp - average grade, %;
Β——single sample position, %;
ι - single length, meter.
2) Sampling weight percentage
Where γ n - sample weight percentage, %;
ι n - the length of the sample corresponding to γn, m;
ι m - the total length of the sample in a certain range of the deposit, meters.
3) Sampling weight
P n =PY n (3)
Where P n is the sampling weight corresponding to γn, in kilograms;
P——The total weight of the ore sample required for the test, kg.
When calculating the length of the sample, it must be noted that the exploration engineering network is the same. If the type of ore is not uniform, the scale factor of the exploration network is applied. For correction, the lengths of the individual samples of the dense exploration project are multiplied by η, and then grouped according to Figure 1, and the average grade, sampling percentage and weight of each group are calculated according to the above formula, and can also be grouped by chemical composition in Figure 1. Above, the increase is grouped according to the reserve level. The sample weight percentage and the average grade of the ore sample or the average grade of the ore body can be calculated by the ore weighting method. [next]
For correction, the lengths of the individual samples of the dense exploration project are multiplied by η, and then grouped according to Figure 1, and the average grade, sampling percentage and weight of each group are calculated according to the above formula, and can also be grouped by chemical composition in Figure 1. Above, the increase is grouped according to the reserve level. The sample weight percentage and the average grade of the ore sample or the average grade of the ore body can be calculated by the ore weighting method. [next] 2, rock samples
(1) The mixing rate of the roof, floor and interlayer of the ore body is provided by the mining design department.
(2) The calculation of the percentage of the mixed rate of various rocks in the roof, floor and interlayer of the ore body is illustrated by the following example:
Where k is the percentage of the rock in the top of the ore body that accounts for the mixing rate of the top plate, %;
N—the number of times the exploration project passes through the same type of rock on the roof of the ore body;
m—The total number of times the exploration project passes through the various rocks on the roof of the ore body.
When the exploration network of the deposit is different, the k value is corrected by the proportional coefficient of different net degrees, that is,
Where n a is the number of times a rare exploration project passes through the top of the ore body;
n b —— the number of times the dense exploration project passes through the same kind of rock on the roof of the ore body;
m a - lean ore exploration project through the total number of roof stone;
m b —— the total number of times the dense exploration project passes through the roof rock of the ore body;
η - the scale factor of the exploration network.
The same rock total mixing rate is calculated by the following formula
K=K top ·R top +K bottom ·R bottom +K clip ·R clip (6)
Where K is the total mixing rate of the same type of rock, %;
Where K is the total mixing rate of the same type of rock, %;
K top , K bottom , K clip - respectively, the mixing rate of the top plate, the bottom plate, the interlayer, %;
R top , R bottom , R clip - respectively, the percentage of the top plate, the bottom plate, the interlayer mixing rate, %;
(3) The weight of various rock samples can be calculated as follows:
Q=qk (7)
Where Q is the sampling weight of a rock, in kilograms;
q——The total weight of the rock sample used for the test, kg.
(4) Preparation of sampling basis
Fill in the results of the calculations in the example in the table below to get the sample basis table.
[next] (5) Select sampling points
The selection of sampling points is mainly based on the sampling basis (or sampling basis), and the following principles should be fully considered:
1. When selecting sampling points, the existing exploration and mining projects in the mine should be fully utilized, and special sampling projects should be avoided as much as possible. The surface sampling points should be placed in the exploration works such as natural outcrops and well-preserved or restored small trenches and shallow wells; the deep samples should be placed in the existing exploration tunnels and mining tunnels as much as possible. Where no exploration tunnels are available, they shall be placed in the exploration bore where the core remains.
2, must take into account the physical and mechanical properties of the ore, such as hardness, humidity, compressive strength, degree of fracture and the amount of mud and other representative.
3. The number of sampling points is as much as possible, especially the sampling interval with large sampling weight percentage. The sampling point is evenly distributed in the ore body space to reduce the impact caused by incomplete control factors. However, the optional test sampling points can be arranged in the shallow part of the ore body, and the sampling points of the beneficiation process, semi-industrial and industrial tests can be arranged in the initial mining section.
4. Select as many as possible, the most complete exploration projects containing ore types and industrial grades as sampling projects, and arrange sampling points to reduce the sampling workload.
5. Appropriate consideration of sampling construction and transportation conditions. Under the premise of not affecting the representativeness of the ore sample, select the location with good construction and transportation conditions as the sampling point.
6. The rock sampling point should be placed within the range of contact with the ore body and the thickness of the surrounding rock during mining.
Fourth, sampling construction and grade verification
(1) Precautions during sampling construction
1. When using existing exploration projects, such as tanks, wells, pit exploration works and natural outcrops of ore bodies, the soil debris and weathering crust on the working surface should be removed first to eliminate the representative impact on the ore samples. If the original tank, well, and pit engineering cannot find the required sampling point position due to collapse damage, the working surface should be cleaned first, and small-scale groove sampling should be performed to re-determine the exact position of the sampling point.
2. When sampling from the core and core, it is generally not allowed to take all the samples preserved in the borehole. Only half of the existing preserved cores and cores can be taken as test ore samples, only in special cases. If the weight of the sample cannot meet the minimum weight required for the test, the core can be removed after consultation with the relevant units. Even in this case, each sample must be delineated during geological exploration. A small number of typical core and core samples should still be retained for inspection.
3. For sampling projects specially designed for excavation, small-scale sampling tests and geological sketches should be carried out before sampling. After affirming the representativeness of the samples, sampling can be performed.
(2) Grade verification
After the ore samples are produced, it is necessary to check whether the ore samples of each grade are in conformity with the required ore samples. Chemical analysis of each grade interval ore sample is required to find out the actual grade and compare it with the average grade required in the sampling basis to find the error value. If the error between the two exceeds the error specified in Table 3, the solution is as follows:
1. When the grade difference is small, you don't need to change it.
2. When the grade value is small, the low or high grade ore in the grade range can be adjusted to the desired grade.
Black metal ore sampling quality tolerance error Table 3
Ingredient content, % | Allow absolute error, % | Ingredient content, % | Allow absolute error, % |
>45 30~45 20~30 15~20 10~15 5~10 1~5 | 1 1 1 0.5 0.5 0.5 0.1 | 0.5~1 0.1~0.5 0.05~0.1 0.01~0.05 <0.01 | 0.05 0.01 0.005 0.002 0.001 |
V. Special problems and solutions during sampling
(1) Incomplete individual information
When sampling, it is often encountered that individual useful components (such as elements that can be comprehensively recovered) can only be combined with sample analysis results. The grade intervals and average grades of the elements cannot be calculated, and the selection basis cannot be provided. In this case, sampling can be selected according to other factors. Point and select small-scale sampling at the selected sampling point position to test the element grade. The sample weight calculated according to Equation 3-3 is then weighted by the weighting method to calculate the element grade for each desired control factor. Comparing the calculation results with the grade of the element of the deposit, if the difference is large, changing or supplementing some sampling points without affecting the representativeness, the weight of each element of the control factor is still calculated by weight weighting method, and then comparing So two or three times can meet the requirements.
(2) Insufficient sample weight
1. The rock and core are kept intact, but the weight cannot meet the requirements of the ore dressing test. At this time, the mining sample can be replenished under the following conditions.
(1) Samples (oxidation degree, grade, type, structure and other factors) similar to rock and core are taken in the surface outcrop, in the exploration project, and in the development roadway to supplement the shortage of sample weight.
(2) For the blind ore body without the development of the roadway, it is necessary to excavate a special sampling project for sampling. The layout of the new roadway is considered as possible for future production.
2. The rock and core are not completely preserved. At this time, the existing rock and core sample should be inspected first. If the type and weight cannot be met, the mining sample can be supplemented under the following conditions.
(1) When the deposit has been supplemented for exploration, the missing ore sample may be taken in the supplementary exploration project.
(2) When the ore is not used for supplementary exploration, the missing ore samples may be taken in the surface exploration project, outcrop and trough, and well exploration engineering.
3. The rock and core have been used up or lost. At this time, the original records of the rock and the core are firstly sorted out, and the types, characteristics and sampling ratios of the rock and the rock are identified, and then treated in the same way as 2, If the constructed geological exploration project is destroyed and the original sampling point cannot be found, then the damaged exploration project should be restored as much as possible, and strive to find the original sampling point. Otherwise, small sampling can be performed at the adjacent sampling point. verification. If the entry is large, the sampling points are rearranged.
(3) The sampling points cannot be evenly arranged
In the mining process, for some reasons, it is often impossible to take a representative sample at the specified sampling point. The sample to be taken can be selected at the existing sampling point. If the sample can reflect the ore characteristics, it is considered to be satisfactory. Claim.
(4) Conditions that are not suitable for sampling
The following conditions are not suitable for sampling in principle:
1. Insufficient exploration.
2. The quality of exploration is inferior and the basic data is incomplete.
3. The distribution of beneficial and harmful ingredients and unclear reserves.
6. Contents of mineral sample packaging and sampling instructions
1. The sample of the mine should be properly packed with a solid container (usually wooden box) to prevent leakage, moisture and easy handling. The weight of each ore sample should be about 50 kg. The registration card should be attached to the box, detailing the type, number, sampling location and actual weight of the sample. The number is also written outside the box for easy identification.
2. Whether different ore types, different industrial grades and different grades of mineral samples are packaged separately, depending on the needs of the test. For example, in the test stage, in order to carry out necessary condition tests and multi-program flow test studies, they should generally be packaged separately.
(2) Contents of sampling instructions
After the sampling work is completed, the sampling unit should be prepared by the responsible sampling unit. The main contents are as follows:
1. Purpose and requirements of the test
2. Brief description of the geological characteristics of the deposit, including the geological structure characteristics of the mining area; the occurrence, size, shape and burial conditions of the ore body; the occurrence conditions and genetic types of the ore body; the classification criteria of the ore type and the mineral composition of each type of ore, Structural structure, inlay characteristics and particle size characteristics; classification criteria of ore industrial grades and average grades and grade changes of main beneficial, harmful and accompanying grades of ore grades; multi-element chemical analysis results of ores of various types and grades; ore oxidation Degree and extent of oxidation zone; spatial distribution and phase-to-relationship of ore of each type and grade; reserves of ore of various types and grades; properties, types, spatial distribution of ore bodies and inclusions of ore bodies and their interaction with ore bodies Relationships, etc.
3. Technical conditions for mining, including mine production and production limits; mining methods, development methods and mining methods; mining area division, mid-section height, mining sequence and mining period; ore product plan; production grade and waste rock in each period Mixing rate, etc.
4, sampling requirements
5. Sampling method, sampling point location selection, mineral sample type, grade, weight list and average grade calculation result table and sampling point distribution position map of each sampling point.
6. Demonstration of the representativeness of the ore sample.
7. Description of the mineral sample packaging, detailing the classification number, variety, packing quantity, box number, weight and total weight of each type of mineral sample.
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