What are the mineral processing tests?

The ore dressing test data is the main basis for the design of the beneficiation process. The results of the ore dressing test not only have a direct impact on the rational determination of the process, equipment selection, product plan, technical and economic indicators of the beneficiation design, but also the basis for whether the ore dressing plant can successfully reach the design index and obtain economic benefits after it is put into production. Therefore, the ore dressing test that provides the basis for the design must be undertaken by a dedicated test research unit. The mineral processing test report shall be reviewed and approved according to relevant regulations before it can be used as the design basis. Before the ore dressing test is carried out, the ore dressing process designer should fully understand the characteristics of the deposit resources, the type and grade of the ore, the characteristics of the ore and the nature of the process, and the optional test. In combination with the mining plan, the test requirements are submitted to the test unit. In general, it is generally not necessary to detail what the test unit should normally do, but rather to highlight the special content and main issues that need to be solved by the test unit.

First, the division of the type of mineral processing test

According to the purpose of the research, the ore dressing test can be divided into three types: optional test, process test and single mineral technology test. According to the test scale, it can be divided into laboratory test, semi-industrial test and industrial test. In order to clarify the requirements of the ore dressing test and the convenience of the description, the above two classifications are summarized, and the types of ore dressing tests are divided into optional tests, laboratory small-scale test, laboratory extended continuous test, semi-industrial test, industrial test and single dressing technology. Six tests were conducted.

(1) Optional test. Generally completed by the geological exploration department. In the stages of geological survey, preliminary survey and detailed survey, the depth of optional test research should be gradually improved and deepened. The optional test focuses on the research and exploration of the differences in the nature and selectivity of various types and grades of ore, the basic beneficiation methods and the possible mineral processing indicators, the difficulty of eliminating harmful impurities, and the possibility of comprehensive recovery of the generated fractions. The content and depth of the experimental study should be able to determine whether the exploration of the ore used in the exploration is technically feasible and economically reasonable, and can provide a basis for the formulation of industrial indicators and mineral deposit evaluation. The optional test is carried out on laboratory equipment or small test equipment, and is generally only used for mineral deposit evaluation.

(2) Small laboratory test in the laboratory. The laboratory small-scale process test is carried out after the completion of the geological exploration of the deposit, before the feasibility study or preliminary design. It focuses on the ore mineral characteristics and beneficiation process characteristics, beneficiation methods, process structure, mineral processing indicators, process conditions and products (including some intermediate products) for experimental research and analysis, and should be tested in comparison with two or more programs. The content and depth of the experimental study. Generally, it should be able to meet the requirements of preliminary formulation of process flow and product plan, selection of main process equipment and comparison of design schemes in the design work. Because the small-scale laboratory test in the laboratory is small in scale, small in sample materials, high in flexibility, and low in effort and material cost, it is allowed to be widely explored in a wide range, and because the sample is easy to mix, the batch operation conditions are easy. Control is therefore the most basic test of each test. However, it is carried out on small non-continuous (or partially continuous) test equipment in the laboratory. The degree of simulation and the reliability of the test results are superior to the optional test, but not as long as the laboratory expands the continuous test.

Table 1 Requirements for beneficiation design of the beneficiation process

Table 2 Requirements for the scale of single mineral technology design of mineral processing design

(3) The laboratory expands the continuous test. The laboratory expands the continuous test by simulating the process of grinding, sorting and even dewatering operations in the industrial production process using laboratory equipment after the completion of the small-scale process test. It focuses on the beneficiation index and process conditions of the process dynamic equilibrium conditions (including the return of the mine). The ability of each test research unit to continuously test equipment is very inconsistent, generally 40 to 200 kg / h. The laboratory extended continuous test is better than the small flow test, and the less reliable process test is higher.

(4) Semi-industrial tests. Semi-industrial tests are carried out in specially established semi-industrial test plants or workshops. The tests can be continuous in the whole process or continuous or stand-alone semi-industrial tests in local operations. The purpose of the test is mainly to verify the process plan of the laboratory test, and to obtain technical and economic indicators similar to the production, to provide a reliable basis for the design of the concentrator or to lay the foundation for further industrial testing. The equipment used in the semi-industrial test is a small industrial equipment. The scale of the pilot plant is not clearly defined, and is generally 1 to 5 t/h.

(5) Industrial testing. The industrial test is a partial or full-process test carried out in a specially established industrial test plant or a series or even a whole plant using the production ore dressing plant. Since the equipment, process and technical conditions are basically the same as the production or future design, the technical economy Indicators and technical parameters are more reliable than semi-industrial tests.

(6) Single technical test of mineral processing. The single-item technical test of mineral processing includes single new technology test and single routine technical test, among which the single new technology test includes new equipment, new technology, new medicine, new material test and so on. Any new technology that has no experience in use must adhere to the principle of “all passing the test” and obtain the technical appraisal data, which is determined by the design unit to be reliable before it can be used in the design.

Second, the scale of mineral processing trials

See Table 1 for the requirements of the dressing design for the trial scale of the beneficiation process. See Table 2 for the requirements of the single-technical test scale.

Third, the content of the ore dressing test

The laboratory small-flow test is the basic test of the beneficiation process test. If the test does not meet the requirements of the design work, the laboratory shall be extended to continuous test, semi-industrial test or industrial test as needed. The latter are based on the content of the former test, the verification, supplement or increase of the test according to the purpose and requirements of the test. The single ore dressing technology test should also start from the small test of the laboratory, and gradually expand the scale of the test. The content of each test should be determined according to the purpose of the test. Before the various types of ore dressing tests as the basis for design, the “test requirements” proposed by the design unit to the test unit, the outlines of the requirements for various types of ore dressing tests are as follows:

(1) Laboratory small-scale process test

1. Study on the properties of raw ore

(1) Spectral analysis. Identify the approximate content of various elements and the presence or absence of rare elements and other elements for comprehensive recovery.

(2) Multi-element analysis or full analysis. Identify the content of major components, associated beneficial and harmful components in the ore. Chemical analysis of the properties of the slurry is also carried out when necessary to determine soluble salts.

(3) Analysis of test funds. Find out the types and contents of gold, silver and other precious metals (including precious metals such as gold and silver).

(4) Microscopic identification. Identify the ore type, mineral composition and content, ore structure, mineral size and embedding characteristics and symbiotic relationship. The analysis of the minerals selected for the purpose of mineral processing.

(5) Phase analysis. The state of occurrence of the main useful components of ore and associated beneficial and harmful components, ie their different forms of mineral production. For example, copper ore needs to determine the relative content of natural copper, primary sulfide, secondary sulfide, oxide and copper salts; iron ore needs to measure magnetite, hematite, siderite, mirror iron The relative content of ore, limonite, pyrite, pyrrhotite, ilmenite and iron silicate.

(6) Particle size analysis. Through the sieve analysis and water analysis, the ore particle size characteristics and the respective grain fraction content and metal distribution rate of the primary slime are determined. If necessary, use different concentrations of heavy liquid to determine the yield and metal distribution rate of each fraction according to different density, which provides a basis for heavy liquid separation.

(7) Heavy wave separation. In the ore and rare metal ore of tungsten, tin, lead, zinc, iron, etc., if it is possible to separate most of the gangue without fine grinding, heavy liquid separation test should be carried out to provide for heavy medium pre-selection test. in accordance with.

(8) Determination of physical and mechanical properties of ore. Density, loose density, angle of repose, internal friction angle, friction coefficient, hardness, viscosity, moisture, specific magnetic susceptibility, electrical conductivity, mud content, etc. of the ore were measured.

(9) Other necessary analytical research content.

2. Experimental study on the grinding process (including washing and pre-selection)

The laboratory should generally perform the following tests and measurements:

(1) Determination of work index. If the calculation of the crushing and grinding equipment is carried out according to the Bond formula, the determination of the crushing and grinding work index should be carried out. The measured work index has the following types: coarse, medium and fine crushing work index; self-hardening work index; rod grinding work index; ball grinding work index; and coarse concentrate or medium ore re-grinding index.

(2) Determination of the grindability. If the grinding method is used to calculate the grinding equipment, the ore grinding degree of each section of the grinding should be determined. In the ore grindability test, the standard ore sample used as a comparative test shall be adopted. The non-ferrous metal ore dressing plant shall design the ore of the Yangjiazhangzi molybdenum ore as the standard ore sample, and the chemical mine pyrite ore dressing plant shall be designed to the mountain. The pyrite ore is a standard ore sample, and the metamorphic phosphate rock is a standard ore sample with Jinping Phosphate ore. The sedimentary phosphorus rock and siliceous calcium phosphate ore are used in the third layer of the mine. The ore is a standard ore sample, and the ferrous metal ore dressing plant is designed to produce the ore of the ore dressing plant as a standard ore sample in a similar grinding process. In view of the often changing nature of the ore mined in the production mine, the standard ore sample should be taken at the same time as the mill processing capacity, technical conditions and relevant technical parameters of the mine at the time of processing the ore.

(3) Abrasion index test. The consumption of grinding media and grinding machine liners is a major consumption indicator of the ore dressing plant, so the consumption index should be determined.

(4) Self-grinding medium performance test. When the self-grinding process is to be adopted, the self-grinding medium test should be carried out first to determine whether a self-grinding or semi-self-grinding semi-work sub-test or industrial test is required.

(5) When studying the grinding process, it should be considered whether it is necessary and possible to wash the mine according to the ore content and the nature of the slime and its influence on the crushing, grinding, sorting and dewatering operations. If it is necessary to wash the mine, it is necessary to carry out the corresponding washing and washing overflow treatment test.

(6) Experimental study on ore pre-selection. The ore pre-selection may be carried out before the original ore is ground, depending on the waste rock mixing rate at the time of mining or the need for enrichment of the ore grade. If possible, an ore pre-selection test is required, and a grinding process for pre-selected ore is included in the grinding process test plan.

(7) Experimental study of grinding methods and grinding processes. Commonly used grinding methods can be divided into ball milling, rod grinding, self-grinding, semi-self-grinding, gravel grinding, etc. depending on the grinding medium. According to the nature and characteristics of the ore, the relevant experimental data, the similar experience of production and testing, and other factors, the possibility of various grinding methods and the necessity of expanding the test should be analyzed, and one or two of the main ones should be selected and recommended. Single or combined grinding method. On this basis, a grinding process or multi-stage grinding, multi-stage continuous grinding or stage grinding (including rough grinding and tailing, medium ore and coarse concentrate re-grinding, etc.) and other grinding processes and grinding fineness Program comparison test.

(8) Analysis of grinding products. The grinding feedstock and products (including medium ore, coarse concentrate, etc.) shall be sieved and the degree of monomer dissociation shall be determined.

C/Z/U purline Molding Machine: this machine is for making the C/Z/U purline for the light steel strutures. C and Z steel purlins are necessary for the modern steel industrial buildings, and workshop as well, and various kinds of C/Z Purlin Roll Forming Machine have been developed to produce C/Z/U steel purlins. We also can make interchangeable c/z purlin roll forming machines and â„¦ shaped purline forming machine.