In order to study the material composition of the deposit, the basic working method of rock and mineral research-counting particle method has been used to quantify minerals in the past. In this method, representative ore samples (large samples) are processed to a particle size below 0. 1mm, and then screened into four particle fractions. Then, the minerals in each particle part are identified under binocular microscope and counted (usually thousands) to calculate the area percentage of minerals. Finally, according to the output of ore samples with different particle sizes and the density of various minerals, the mineral content percentage of various minerals in large samples is calculated by weighting. This method is often inaccurate because it is difficult to directly identify minerals; The existence of symbionts and inclusion bodies affects the accuracy of quantification; Fine-grained ore samples (slime) cannot be qualitatively and quantitatively, so the calculation based on the composition of adjacent fractions is insufficient. This makes this method usually only semi-quantitative accuracy in mineral quantification, but the error is even greater for trace and small amounts of rare element minerals. Therefore, how to improve the quantitative accuracy of minerals in this kind of ore is one of the difficult problems in the study of mineral composition.
In this project, according to the basic law of mineral composition analysis, niobium, rare earth elements and most of the elements in the sample with a content greater than 0.0 1% are counted as 19, namely niobium, rare earth, iron, manganese, silicon, phosphorus, fluorine, calcium, magnesium, carbon dioxide, barium, strontium and titanium. The determination of the chemical composition of a single mineral in the calculation of ore quantity is based on the analysis results of a single mineral. For a few minerals that are difficult to extract, refer to the average value of minerals contained in the data. Conversion of mineral quantity from phase analysis results. According to different situations, 1 ~ 2 element (component) is selected as the characteristic element of a mineral, and the number of minerals is calculated according to the chemical composition of a single mineral, and at the same time, the multi-element composition of each mineral is calculated, and finally the number of 3 1 mineral in a large sample is calculated. The research process, data and conclusions are summarized as follows:
Multi-element analysis of (1) ore samples
40 items of the volumeter were quantitatively analyzed, and some components such as F, Mn, Fe2O3, S, etc., which were in contradiction with the measured state, were corrected according to the results of phase analysis. The total amount of total analysis is 99.85%, and the results are listed in Table 2. 16.
Table 2. Multielement Analysis Results of16 Large Samples (wB/%)
(2) Separate determination of mineral quantity
Because of some characteristics of phase analysis, the design of mineral phase separation is slightly different from the routine work of rock and ore, for example, niobium minerals are divided into finer ones, while silicate minerals are coarser.
This research work is carried out simultaneously with the application of traditional particle counting method in rock and mineral methods, which divides large samples into four particle parts. In order to ensure the accuracy of the phase analysis results, the phase analysis of the large sample and the sub-samples of four particle fractions were carried out at the same time, and the phase-by-phase equilibrium calculation was carried out. See Table 2. 17 for the quantity and output of the four fractions.
Table 2. 17 Classification of Large Sample Size and Output
1. Quantification of niobium minerals
The phase analysis of niobium in large sample (Bo) and four kinds of particle size samples was carried out by using the phase analysis method of niobium in ore deposits specially studied (see chapter 1). According to the specific conditions of the deposit, soluble stone, yellow-green stone, niobite, niobite, ilmenite, rutile and dispersed phase were determined, and the results are listed in Table 2. 18.
Table 2. Phase analysis of niobium in18 large sample and four particle fractions (w (Nb2O3)/%)
According to Table 2. 18, the mineral contents of various niobium minerals can be calculated as follows: soluble stone 0.0 1%, yellow-green stone 0.0 1%, calcium niobate 0.0 1%, niobite 0.07%, and ilmenite rutile 0.01.
From the results of Table 2. 18, it can be seen that niobium mainly exists in the form of niobite (the phase analysis results of the other two kinds of ores in this mine show that niobium in the form of niobite accounts for 79.6% of the total niobium in dolomite primary ore and 75.9% in dolomite oxidized ore). The dispersed phase of niobium in the table is obtained by solvent leaching, and some of them are independent minerals embedded with niobium with fine particle size, except that they exist in various non-niobium minerals in isomorphic state.
2. Quantification of rare earth minerals
The rare earth minerals in this mining area are quantitatively analyzed by the specially studied phase analysis method (see the second and third sections of Chapter 1). Three phases of large samples and four particle fractions, namely fluorocarbon, monazite and niobate, were mainly determined, and the results are listed in Table 2. 19.
According to the results in Table 2. 19, it is calculated that the mineral content of various rare earth minerals is 1. 17% and monazite is 0.92%.
3. Quantification of iron minerals
Iron is the main component of this mining area. The phases of magnetite, pseudohematite, hematite, limonite, iron carbonate, pyrite, pyrrhotite and iron silicate have been determined, and the results are listed in Table 2.20.
Table 2. 19 Rare Earth Phase Analysis Results (w(RE2O3)/%)
Note: 0.025% of other minerals are isomorphic or highly dispersed.
Table 2.20 Phase Analysis Results of Iron (w(Fe)/%)
See chapter 1 section 14 for the phase analysis method of iron. The analysis process used in this sample is as follows: firstly, iron carbonate is leached by aluminum chloride method, and magnetic iron is separated at the same time. Take the magnetic part and dry it with bromine. Pyrrhotite is leached with methanol, remanence is determined with Fe2+ and Fe3+, and magnetite and pseudohematite are calculated. Take the non-magnetic part, filter off the water, and use HCl? Hematite and limonite are leached by stannous chloride cold leaching method, and the residues are iron silicate and pyrite. In addition, limonite is determined by oven constant weight method, and hematite is calculated by subtraction. Then weigh the samples separately with HCl? SnCl2 treatment, pyrite is determined by pyrite retention method, and ferric silicate is calculated by subtraction method. According to the results of iron phase analysis, the mineral content can be calculated as follows: magnetite 9.32%, pseudohematite 22.5%, hematite 8.72%, limonite 8.90%, pyrite 0.02% and pyrrhotite 0. 1 1%.
4. Quantification of manganese ore
Five phases, such as magnetite manganese, manganese carbonate, hydromagnesite, pyrolusite and manganese silicate, were determined, and the results are listed in Table 2.438+0.
Table 2.2 Phase Analysis Results of1Mn (w(Mn)/%)
The phase analysis method used is as follows: the magnetic iron mineral phase is separated by wet external magnetic separation, the nonmagnetic water phase is adjusted to 100mL HCl( 1+23), the carbonate phase is leached by shaking at room temperature 1h, and the residue is 50mL H2SO4( 1+ 17). Leaching pyrolusite, leaching residue with 20ml of 200g/L hydroxylamine hydrochloride for 65 05min at room temperature. Finally, the residue is silicate phase. According to the phase analysis of manganese, it can be calculated that the mineral content of manganese ore is pyrolusite 0.26% and hydromagnesite 2.65%.
5. Quantification of timely and silicate minerals.
Time, mica and amphibole were determined, and the results are listed in Table 2.22.
The phase analysis method is as follows: the determination of time is based on phosphoric acid dissolution selective retention time method. In addition, weigh 0.2g sample, treat 1h with 100mL HCl( 1+2) boiling water bath to leach mica minerals (mainly biotite and phlogopite in this sample), and add 20mL 30g/L tartaric acid solution and 10mL HBF4 before filtering to ensure that the solution will not precipitate. The filtrate was separated, and the silica in mica was determined by absorption spectrophotometry, and the residue was amphibole (mainly tremolite, sodium amphibole and amphibole in this sample).
The SiO _ 2 value of the last two phases will be used as the characteristic element for calculating the mineral quantity of this kind of silicate minerals (the average SiO _ 2 in mica is 465,438+0.20%, and that in amphibole is 257.06%). According to the phase analysis of silicon, the timely mineral content is 2. 10%, and the mica mineral content is 19.88%.
Table 2.22 Phase Analysis Results of Silicon (W (SiO _ 2)/%)
6. Quantification of phosphate rock
The apatite and monazite were measured and calculated, and the results are listed in Table 2.23.
Table 2.23 Phase Analysis Results of Phosphorus (w(P)/%)
Phase analysis method: Weigh 0. 1g sample in apatite phase system, add 50mL HNO3( 1+99), boil slightly 1h, and determine the phosphorus in the leachate. The phosphorus system in monazite is converted from rare earth in monazite state according to the composition of single mineral analysis (RE2O3/P2O5 is 57.2/25.8). From the phase analysis of phosphorus, the mineral content of apatite can be calculated to be 2.09%.
7. Quantification of fluorine minerals
The four phases of fluorite, fluorocarbon, monazite and mica were measured and calculated, and the results are listed in Table 2.24.
Table 2.24 Phase Analysis Results of Fluorine (w(F)/%)
The phase analysis method is briefly described as follows: 0.2 g fluorite phase sample is leached by boiling 50 ml100g/L aluminum chloride aqueous solution for 30 minutes, and fluorine in the leaching solution is determined by fluoride ion selective electrode. A large amount of aluminum chloride is added to the standard. The fluorocarbon phase and monazite phase are calculated according to the chemical composition of single mineral based on the total amount of rare earth in this phase, and mica is calculated according to the chemical composition of single mineral based on the SiO2 _ 2 result of this phase. According to the phase analysis of fluorine, it can be calculated that the mineral content of fluorite is 2.09%.
8. Quantification of calcium minerals
Seven items, such as fluorite, apatite, mica, amphibole, calcite, dolomite and fluorocarbon, were measured and calculated, and the results are listed in Table 2.25.
Table 2.25 Calculation Results of Phase Analysis and Distribution of Calcium (w(CaO)/%)
The phase analysis method is briefly described as follows. Fluorite phase is transformed into fluorine (F/Ca is 48.00/50.25), apatite phase is transformed into phosphorus, and mica and amphibole are transformed into SiO2 _ 2. As a result, calcite and dolomite phases are determined according to the method of calcite carbonate mineral phase analysis in Chapter 1, and fluorocarbon phase is transformed into rare earth content in this phase. From the phase analysis of calcium, it can be calculated that the mineral content of calcite is 4.33%.
9. Quantification of magnesium minerals
Three phases, dolomite, mica and amphibole, were determined. The phase analysis method and replacement algorithm are the same as those of calcium, and the results are listed in Table 2.26.
According to the phase analysis of calcium and magnesium, the mineral content of dolomite can be calculated as 4.93%.
10. Calculation of carbon dioxide distribution
Calcite, dolomite and fluorophosphate are calculated according to carbonate minerals, and the results are listed in Table 2.27.
Table 2.26 Calculation results of phase analysis and distribution of magnesium (w(MgO)/%)
Table 2.27 Partition Calculation of Carbon Dioxide (w(CO2)/%)
Among them, calcite and dolomite are converted into calcium and magnesium according to theoretical composition, and fluorocarbon is converted into single mineral chemical composition according to the total amount of rare earth in this phase. From the distribution calculation, it is balanced, which shows that the corresponding results are basically reliable.
1 1. Quantification of barium and strontium minerals
Four phases of plagioclase, fluorocarbon, barite and barium-iron-titanium were determined. The results are listed in tables 2.28 and 2.29.
Table 2.28 Phase Analysis Results of Barium (w(Ba)/%)
For its phase analysis method, please refer to section 6 of chapter 1. According to the phase analysis of barium and strontium, the mineral content is calculated, which is 0.25% for barium-iron-titanium and 0.33% for barite.
65438+
Four phases of ilmenite, rutile, niobate titanate and silicic acid were determined, and the results are listed in Table 2.30.
Table 2.29 Phase Analysis Results of Strontium (w(Sr)/%)
Table 2.30 Phase Analysis Results of Titanium (W (TiO _ 2)/%)
See section 28 of chapter 1 for the phase analysis method. According to the phase analysis of titanium, the mineral content can be calculated, which is 0.06% for rutile and 0.28% for ilmenite.
13. Quantification of chromium minerals
Fluorophosphate, acid-soluble zirconium and zircon were determined, and the results are listed in Table 2.3 1.
Table 2.3 Phase Analysis Results of1Zirconium (w(ZrO2)/%)
The flow chart of phase analysis is as follows: in fluorocarbon system, 0.5g sample is leached with 100mL HCl( 1+7) boiling water bath 1h, the residue is burned, heated with 10mL H2SO4, and acid-soluble zirconium is leached with smoke 15 ~ 20min.
The results of phase analysis show that the zirconium in this sample is mainly zircon, and its mineral content is 0.0 1%.
14. Quantification of lead, zinc and copper minerals
The phase analysis of lead identified oxide phases (lead alum and galena), galena and iron-bound lead. The phase analysis of zinc determines oxide, sphalerite and iron-bound zinc. Because of its low content, only oxide and sulfide phases are determined in the phase analysis of copper. The results are listed in tables 2.32, 2.33 and 2.34.
Table 2.32 Phase Analysis Results of Lead (w(Pb)/%)
Table 2.33 Phase Analysis Results of Zinc (w(Zn)/%)
Table 2.34 Phase Analysis Results of Copper (w(Cu)/%)
15. Distribution balance of sulfur
According to the theoretical composition of minerals, the distribution balance of sulfur is: sphalerite 0.002%, galena 0.0 14%, chalcopyrite 0.00 1%, pyrite 0.01%,barite 0.056% and pyrrhotite 0.038%.
Balance of other elements.
Other elements, such as Scandium, Beryllium, Cadmium, Nickel, Cobalt, Vanadium and Molybdenum, are mainly analyzed by single minerals and calculated according to the mineral quantity of single minerals. As can be seen from the results in Table 2.35, most of them are basically in equilibrium, and thorium is probably an independent mineral of thorium.
(3) Determination results of mineral content in ore.
Details are composed of many minerals, each of which is composed of one or more elements, and different minerals have their own chemical compositions.
Table 2.35 Analysis Results of Large Samples and Mineral Content (wB/%)
sequential
sequential
sequential
Table 2.36 Balance Table of Mineral Quantity of Various Grades in Large Samples
Note: After classification, the coarse-grained samples are further ground to 0.074mm for analysis, and the degree of dissociation of mineral monomers is different, so the mineral quantities of hematite and pseudohematite cannot be balanced independently, and only the sum of the two minerals can be used.
The phase analysis of 19 element in large samples was studied, and the mineral content of 3 1 mineral was calculated according to the results of single mineral analysis. The results are summarized in Table 2.35. As can be seen from the horizontal data in Table 2.35, the content of each element (component) is listed for each mineral, and its proportion is consistent with the chemical composition of a single mineral, and the sum of each element (component) is its mineral quantity. As can be seen from the longitudinal data in Table 2.35, the proportion of each element (component) in various minerals is listed, and its sum is consistent with the results of elemental analysis of large samples. After phase correction, the total analysis sum of large samples is 99.85%, and the sum of mineral quantity of 3 1 00.5438+0%. The whole set of data shows that the determination results of mineral content in large samples provided by phase analysis method are reasonable.
According to the same method, the four particle fractions of the large sample were quantified by 3 1 mineral, and the comprehensive balance was made. The results are shown in Table 2.36.
Research conclusion: The mineral composition of mica amphibole oxide ore in an iron ore body in Inner Mongolia was studied by chemical phase analysis method, and the phase analysis and partition calculation of 19 elements (niobium, rare earth, iron, manganese, silicon, phosphorus, fluorine, calcium, magnesium, carbon dioxide, barium, strontium, titanium, zirconium, lead, zinc, copper, etc.) were carried out. ) has been studied. Number of 365,438+0 minerals (magnetite, pseudohematite, hematite, limonite, amphibole, mica, fluorite, apatite, timely, pyrolusite, bischofite, sphalerite, galena, galena and galena, dolomite, calcite, zircon, fluorocarbonate, monazite, chalcopyrite, pyrite, etc.) ) are determined.
The whole study pays attention to two equilibria, namely, the phase-by-phase weighted equilibrium of the phase analysis results of 67 phases between the large sample and its four particle size samples, and the element (component) item-by-item equilibrium of 3 1 mineral calculated according to its chemical composition of single mineral and the total analysis of the large sample. These two comprehensive equilibria fully explain the rationality of the mineral composition results provided.