Preparation method of magnetic hematite mixed iron ore flotation test standard sample

Abstract

The invention relates to the field of magnetic hematite mixed iron ore flotation. According to the preparation method of the magnetohematite mixed iron ore flotation test standard sample, a sampling device is installed on an ore inlet pipe at the position 2 m away from the front end of a flotation ore feeding pump, and the sampling device comprises a steel pipe and a control valve installed on the steel pipe; determining field indexes suitable for taking a standard sample according to the field operation condition in combination with flotation test data developed in the earlier stage; a multi-batch mixed sampling mode is adopted for sampling, and small samples are taken while large samples are taken; carrying out particle size detection and flotation evaluation tests by using the small samples, re-sampling the small samples which do not meet the requirements and the corresponding ocean, standing and clarifying the large samples corresponding to the small samples which meet the requirements, extracting supernatant liquid, taking residual ore pulp back to a test room, drying and uniformly mixing; carrying out particle size detection and flotation evaluation test on the uniformly mixed sample again, and bagging the sample to be used as a standard sample if the sample meets the requirement; if not, the sample is used for other purposes, and a standard sample is prepared again.

Description

Technical Field

[0001] The invention relates to the field of maghemitic mixed iron ore flotation. Background Art

[0002] Flotation refers to the use of surfactants - frothers that can generate a large number of bubbles. When air is introduced into the water or air enters the water due to the agitation of the water, the hydrophobic end of the surfactant is oriented toward the air side of the bubble at the gas-liquid interface, and the hydrophilic end remains in the solution, forming bubbles; another surfactant that acts as a capture agent (usually cationic surfactants, including fatty amines) is adsorbed on the surface of solid mineral powder. This adsorption has a certain selectivity depending on the nature of the mineral. Its basic principle is to use the lattice defects on the crystal surface, and the outward hydrophobic end is partially inserted into the bubble, so that during the flotation process, the bubble may take away the specified mineral powder, achieving the purpose of mineral separation.

[0003] Flotation standards are standard samples used to calibrate and verify flotation equipment, process parameters and operator skills during the flotation process. By using standard samples, the stability and repeatability of the flotation process can be ensured, thereby improving the quality and efficiency of ore processing.

[0004] The standard samples for the flotation test of hematite mixed iron ore are mainly used for the evaluation test of flotation factors such as flotation reagents and mineral processing circulating water, and for conducting small-scale flotation tests to check flotation influencing factors when the indicators are abnormal. The standard samples prepared by the existing technology are unstable, and it often happens that the indicators meet the sampling requirements during sampling, but the samples taken out have large fluctuations. The flotation indicators of standard samples with particularly good grade and particle size are good, and the fluctuation of a certain flotation influencing factor cannot cause the change of the flotation indicator; when the grade and particle size are poor, even if a single-factor flotation test is carried out, the flotation influencing factors cannot be found out. Summary of the invention

[0005] The technical problem to be solved by the present invention is: how to prepare a flotation test standard sample with stable performance and strong representativeness.

[0006] The technical solution adopted by the present invention is: a method for preparing a standard sample for a flotation test of a mixed hematite ore, which is carried out as follows: 1. Determine the appropriate sampling position and install a sampling device on the ore inlet pipe 2m from the front end of the flotation feed pump. The sampling device includes a steel pipe and a control valve installed on the steel pipe; 2. According to the on-site operation conditions and combined with the flotation test data carried out in the early stage, determine the on-site indicators suitable for taking standard samples; 3. Sampling: Sampling adopts the method of multi-batch mixed sampling, taking large samples and small samples at the same time to ensure the strong representativeness of the samples; 4. Use small samples to carry out particle size detection and flotation evaluation tests. For small samples that do not meet the requirements and their corresponding large samples, resample them. The large samples corresponding to the small samples that meet the requirements are allowed to stand for clarification and the upper clear liquid is extracted. The remaining slurry is taken back to the laboratory for drying and mixing. 5. After mixing, the samples are again subjected to particle size detection and flotation evaluation tests. If they meet the requirements, the samples are bagged and used as standard samples. If they do not meet the requirements, the samples are used for other purposes and new standard samples are prepared.

[0007] The on-site indicators are: the mineral processing system indicators are stable for more than 48 hours, the flotation concentrate grade is 65%~66%, the flotation tailings grade is ≦18%, the flotation feed grade is 40%~42%, and the flotation feed -325 mesh particle size is 90~92%.

[0008] When sampling, sampling began 3 minutes after the slurry flowed out. The ocean sampling was divided into 10 batches, with an interval of 1 hour between each batch. Each batch sampled 30L, for a total of 300L. When each batch of ocean sampling was taken, a 1L sample bucket was used to take a small sample of 1 bucket.

[0009] When using small samples for particle size detection and flotation evaluation tests, take 30g of ore sample and screen it with water to -325 mesh particle size to detect whether its particle size meets the standard of 91±1% and whether the flotation concentrate grade is >65%.

[0010] When standing for clarification, the standing clarification time should be ≥ 72h. When the water quality of the upper clarified liquid is <300ppm, the upper clear liquid should be extracted using a hose using the siphon principle. Direct dumping is strictly prohibited. The height of the remaining upper clear liquid must not be less than the thickness of the sedimentation layer.

[0011] When drying, the drying time should be ≥ 24h. After all the samples are dried, crush and mix them evenly.

[0012] When the mixed samples are subjected to particle size detection and flotation evaluation tests again, 30g of the ore sample is taken by multiple reduction method for water analysis and screening to -325 mesh particle size to detect whether its particle size meets the standard of 91±1%; 200g of the ore sample is taken for flotation test to detect whether the grade of the flotation concentrate is >65%.

[0013] If the requirements are met, the samples will be bagged, 200g per bag, and used as standard samples.

[0014] The beneficial effects of the present invention are as follows: the standard sample prepared by the present invention has stable performance, can accurately evaluate the influence of factors such as flotation reagents and mineral processing circulating water on flotation, and accurately guide on-site process operations; the method of the present invention can quickly and accurately prepare standard samples that meet the requirements, reducing the waste of manpower and material resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is an overall schematic diagram of an embodiment of the present invention. DETAILED DESCRIPTION

[0016] like Figure 1 As shown, the flotation test standard sample of the mixed hematite ore is carried out in the following manner.

[0017] 1. Install a sampling device on the ore inlet pipe 2m from the front end of the flotation feed pump. The sampling device includes a DN50 steel pipe and a control valve installed on the steel pipe. The diameter of the sampling pipe is 50mm to ensure that the slurry flow is smooth, stable and will not spray during sampling; the sampling position is on the ore inlet pipe 2m from the front end of the flotation feed pump to ensure the representativeness of the sample.

[0018] 2. Sampling conditions: The indicators of the mineral processing system are stable for more than 48 hours, the flotation concentrate grade is 65%~66%, the flotation tailings grade is ≦18%, the flotation feed grade is 40%~42%, and the flotation feed -325 mesh particle size is 90~92%.

[0019] 3. When the production site conditions meet the sampling conditions, start sampling. Open the sampling valve, and start sampling 3 minutes after the slurry flows out. The ocean sampling is divided into 10 batches, with an interval of 1 hour between each batch; each sampling is about 30L, and a total of about 300L is sampled; when taking a large sample from each batch, use a 1L sample bucket to take a small sample. Take a small sample at the same time as taking a large sample, pre-test the particle size and flotation performance of the ore sample, and deal with unqualified samples in advance to reduce the waste of manpower and material resources. Mix multiple batches of sampling, 10 batches into 1, to eliminate sample fluctuations.

[0020] 4. Filter, dry and mix the 10 batches of sample pulp taken from the 1L sample barrel. Take 30g of the ore sample for water analysis and screening to -325 mesh particle size to test whether its particle size meets the standard of 91±1%; take 200g of the ore sample for flotation test to test whether the flotation concentrate grade is >65%. If the indicators meet the requirements, the on-site samples will begin to be clarified; if the indicators do not meet the requirements, re-sample and re-test.

[0021] 5. The ore slurry that meets the requirements shall be allowed to stand and clarify on site for ≥72 hours, and the water quality of the upper clarified liquid shall be <300ppm. The upper clear liquid shall be extracted using a hose by the siphon principle, and direct dumping is strictly prohibited. The height of the remaining upper clear liquid shall not be less than the thickness of the sedimentation layer. Use the siphon principle to pump water, and dumping is strictly prohibited to prevent the loss of fine-grained ore samples.

[0022] 6. After extracting the upper clear liquid, take the slurry back to the laboratory, filter all the upper mobile parts, and put them in the oven after filtering; the lower sediment layer is directly put in the oven. The sample drying time is ≥ 24h. After the samples are completely dried, crush and mix them.

[0023] 7. After mixing, use the method of multiple reduction to take 30g of the ore sample, water analysis and screening to -325 mesh particle size, and test whether its particle size meets the standard of 91±1%; take 200g of the ore sample for flotation test to test whether the flotation concentrate grade is >65%. If it meets the requirements, the sample will be bagged, 200g per bag, and used as a standard sample; if it does not meet the requirements, the sample will be used for other purposes and the standard sample will be re-prepared.

[0024] The invention can quickly prepare qualified flotation test standard samples, accurately evaluate the influence of factors such as reagents and water on flotation, and quickly and accurately guide on-site production adjustments.

Claims

1. A method for preparing a standard sample for a maghemitic mixed iron ore flotation test, characterized in that: Proceed as follows 1. Determine the appropriate sampling position and install a sampling device on the ore inlet pipe 2m from the front end of the flotation feed pump. The sampling device includes a steel pipe and a control valve installed on the steel pipe; 2. According to the on-site operation conditions and combined with the flotation test data carried out in the early stage, determine the on-site indicators suitable for taking standard samples; 3. Sampling: Sampling adopts the method of multi-batch mixed sampling, taking large samples and small samples at the same time to ensure the strong representativeness of the samples; 4. Use small samples to carry out particle size detection and flotation evaluation tests. For small samples that do not meet the requirements and their corresponding large samples, resample them. The large samples corresponding to the small samples that meet the requirements are allowed to stand for clarification and the upper clear liquid is extracted. The remaining slurry is taken back to the laboratory for drying and mixing.

5. After mixing, the samples are again subjected to particle size detection and flotation evaluation tests. If they meet the requirements, the samples are bagged and used as standard samples. If they do not meet the requirements, the samples are used for other purposes and new standard samples are prepared.

2. The method for preparing a standard sample for a maghemitic mixed iron ore flotation test according to claim 1, characterized in that: The on-site indicators are: the mineral processing system indicators are stable for more than 48 hours, the flotation concentrate grade is 65%~66%, the flotation tailings grade is ≦18%, the flotation feed grade is 40%~42%, and the flotation feed -325 mesh particle size is 90~92%.

3. The method for preparing a standard sample for a maghemitic mixed iron ore flotation test according to claim 1, characterized in that: When sampling, sampling began 3 minutes after the slurry flowed out. The ocean sampling was divided into 10 batches, with an interval of 1 hour between each batch. Each batch sampled 30L, for a total of 300L. When each batch of ocean sampling was taken, a 1L sample bucket was used to take a small sample of 1 bucket.

4. The method for preparing a standard sample for a maghemitic mixed iron ore flotation test according to claim 1, characterized in that: When using small samples for particle size detection and flotation evaluation tests, take 30g of ore sample and screen it with water to -325 mesh particle size to detect whether its particle size meets the standard of 91±1% and whether the flotation concentrate grade is >65%.

5. The method for preparing a standard sample for a maghemitic mixed iron ore flotation test according to claim 1, characterized in that: When standing for clarification, the standing clarification time should be ≥ 72h. When the water quality of the upper clarified liquid is <300ppm, the upper clear liquid should be extracted using a hose using the siphon principle. Direct dumping is strictly prohibited. The height of the remaining upper clear liquid must not be less than the thickness of the sedimentation layer.

6. The method for preparing a standard sample for a maghemitic mixed iron ore flotation test according to claim 1, characterized in that: When drying, the drying time should be ≥ 24h. After all the samples are dried, crush and mix them evenly.

7. The method for preparing a standard sample for a maghemitic mixed iron ore flotation test according to claim 1, characterized in that: When the mixed samples are subjected to particle size detection and flotation evaluation tests again, 30g of the ore sample is taken by multiple reduction method for water analysis and screening to -325 mesh particle size to detect whether its particle size meets the standard of 91±1%; 200g of the ore sample is taken for flotation test to detect whether the grade of the flotation concentrate is >65%.

8. The method for preparing a standard sample for a maghemitic mixed iron ore flotation test according to claim 1, characterized in that: If the requirements are met, the samples will be bagged, 200g per bag, and used as standard samples.

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