FI100310B - A flotation - Google Patents

Description

100310 FOAMING METHOD

ENGINEERING

5

The invention relates to mineral enrichment and relates to an automatic flotation method and apparatus. The invention can be used to perform flotation experiments in laboratories.

10 TECHNICAL BACKGROUND

When flotation experiments are performed on a laboratory scale, the reproducibility of the experiments is very important to achieve the comparability of the experiments. Test results obtained with a slight change in the condition factors cannot be reliably compared unless the same basic test can be repeated with sufficient accuracy.

To improve reproducibility, an automatic foaming machine can be used which, according to a pre - programmed program, carries out the necessary operations from the dosing of the chemicals to the condition measurements and the peeling (see.

20 e.g., Int J Min Proc 10 (1983) 165).

DESCRIPTION OF THE INVENTION

General description: 25

An automatic flotation method according to claim 1 has now been invented. Preferred embodiments of the invention are set out in the other claims.

• · * · · I ”It is essential in the invention that the dry weight of the flotation concentrate (water + solid) is determined after flotation without filtration of the product. Chemical analysis of a filter cake sample taken from the concentrate is also possible immediately with the aid of a separate analyzer. This makes it possible to quickly obtain an overall • · ·: lumbar picture of the course of the experiment at different stages (intake and concentration for the desired elements) and. if desired, adjustment measures may be performed during the test. This gives '··' ·. 35 reduced the number of trials and shortened the time span of the study.

i '. · The reproducibility of the experiments is considerably better in machine tests than in * * "' · tests.

2 100310

Special description

An embodiment of the invention will now be described in detail with reference to the accompanying drawings, in which Figure 1 shows a side view of a test apparatus.

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An automatic flotation robot has now been developed which, with the help of the parameters programmed into it, can perform the entire flotation test with its various steps and report the results without the operator intervening during the test.

10 The main components of the equipment are the flotation machine 1, the chemical dosing units 2 and 3, the scale 4 and the control and printing equipment 5.

The flotation machine 1 has a flotation cell 6, a gas supply device 7, a chemical supply device 8, a mixer 9, conditions measuring sensors 10, a level measuring sensor 11 and a foam peeling mechanism 12.

The chemical dosing units 2 and 3 have tanks 13 and pumps 14, by means of which the desired liquids can be dispensed from the tanks through the chemical supply equipment 8 into the cell 6.

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The control and printing equipment 5 has a meter cabinet 15 (which includes, among other things, pH, potential and conductivity meters), pulse converters for dosing pumps 16, a HIMA logic unit 17, two computers 18 and a printer 19.

:: 25 The gas supply system 7 has proportional valves through which the desired gas flow can be supplied.

• · 3 100310

The addition of chemicals works with machine automation with good reproducibility. This allows for a similar “history of experiments” (pH and redox potential conditions follow the same path). Better reproducibility of similar conditions, in turn, allows for similar results in different experiments.

The foam peeling mechanism has automatic scrapers. In this way, the mechanical performance of the peeling is as similar as possible in different experiments and, for example, the removal rate of the concentrate remains constant. Repeatability is substantially better than 10 manual experiments, especially those performed by different individuals.

The level control automatically makes the foam peeling work well. It also makes it possible to determine the dry weight of the flotation concentrate. This, in turn, allows for more accurate monitoring and evaluation of the course of the experiment, 15 and orientation already during the experiment. This is especially useful in the case where some previous type of experiment is repeated. An example is experiments in which, at the beginning of the experiment, it is desired to carry out repeated foaming or similar follow-up operations on the foamed pre-concentrate under different conditions. In this case, of course, the first half of the experiment should be repeated as similarly as possible, so that the different circumstances of that desired phase alone would change the outcome of the experiment and there would be clear grounds for drawing conclusions.

Another advantage of experimental automation is that the robot can be programmed to run: \. long multi-stage experiments in the country alone, and the time of the experimenter does not need to be:: 25 tied to it. The time freed up by the contractor can be used for other purposes, because in addition to adjusting the conditions of a traditional test run, the robot also takes care of storing the conditions in memory and prints them at the desired level at the end of the test.

S · · • · · · · # ♦ · "1 1 30 The apparatus operates according to a pre-programmed recipe in the logic unit, carrying out the following main steps:« «« ♦ · · · ♦ ·: - pH and potential conditions of the solid-aqueous suspension in the flotation cell: · Will be provided for the program areas with pre - selected chemicals.

35 - The desired amounts of various chemicals are added to the cell, in the desired order, as-. coat them for the desired time, stirring.

4 100310 - The desired amount of gas is blown into the cell, dispersing for the desired time with a mixer and peeling the foam from the surface of the cell into another container.

- The solids content of the foamed product (= dry weight of the product) is determined on the basis of the net weight of 5 products and the volume (= the amount of replacement water added to the cell during flotation) using an approximation of the specific gravity of the product.

- The desired condition measurements, etc. The quantities characterizing the experiment are stored in the logic-10 unit and can be printed from there at the end of the experiment as reports of different degrees.

- The chemical analysis of the resulting foaming product can be performed immediately by taking a sample of the filter cake and performing the analysis with a suitable analyzer (eg ACA, fluorescence analyzer). The results can be quickly used to further control the experiment.

The determination of the dry weight directly from a sample in the form of a slurry is based on the utilization of the total weight and volume of the slurry sample by assuming a certain density for the solid. The density approximation, in turn, is obtained on the basis of the predicted mineralogical composition of the concentrate, either directly from preliminary experiments or on the basis of the mineralogical analysis of the feed material, assuming a specific composition for the concentrate.

• '.. The total volume of the sludge (V ^) consists of two parts: the volume of water. ; 25 desta (Vpi20) And the volume of a solid, which in turn is equal to its mass divided by its density (Vk = Mk / pk). So also the total weight of the concentrate sludge >>>>: consists of two parts Mt0t = Mk + Mh20 · in the method • «on the same principle. deducted from the total weight of the concentrate directly to the volume of water corresponding to its volume.

j «J

• j; * r weight, which has the same numerical value as the volume (g <=> ml because the water ti- * · ’* 30 heys is 1 g / cm ^).

Vtot = VH20 + Vk (1)

Mtot = MH 2 O + Mk (w / wk) (2) 35 The difference obtained is the coarse sub-value of the desired dry weight. It is a sub-value because instead of the actual weight of the water, the amount of water corresponding to the volume of solids has also been reduced. Therefore, it must be corrected by multiplying it by the factor pk / (pk - 1). The sub - value represents the value of pk - 1 itself (the weight of the amount of water corresponding to the volume of solids il 5 100310 was reduced too much because the amount of water corresponding to the whole volume was reduced). The actual weight naturally represents the value pk and the ratio / (pk - 1) thus corrects the dry weight value to the correct dry weight.

5 Using equations (1) and (2), this formula can be derived as follows. When the right sides of the equations are subtracted from each other, an approximation to the dry weight called the above-mentioned sub-value of the dry weight is obtained.

MH 2 O + Mk - (Yh 2 O + Vk) = Sub-value for Mk 10 MH 2 O + Mk - Mh 2 O - Mk / pk = Sub-value for Mk (Mh 2 O = VH 2 O; Mk / Pk = Vk) Mk - Mk / pk = Sub-value for Mk Pk Mk - Mk = Pk x Sub-value Mfcdle (pk - 1) Mk = pk x Sub-value Mk · 'Ile 15 Mk = (Pk / (Pk - 1)) x Sub-value for Mk

The actual dry weight of the sludge sample is thus obtained from that sub-value by correcting it with a correction factor formed from the density of the solid, as described above, and the formula for determining the dry weight thus takes the form 20

Mk = (Pk / (Pk - 1)) (Mtot - Vtot) where Vtot = Vh20 = Mh20 added

Mtot and Vtot must, of course, be converted to the same units Mt0t / g and Vtot /: ‘· .. ml Vtot / g, the latter being converted to the weight of water in ml g and the formula applies: as described above.

• ·

The rapid implementation of the wet weight determination (the continuation of the test does not allow the product to dry) makes it possible to determine the complete result of the tests during the test, even if the tests are accompanied by the possibility of rapid analysis. This can be accomplished, e.g., by taking a small slurry sample from the test product, which is filtered, and the approximate analysis is determined from this moist filter cake, e.g., by an X-ray analysis device. This provides fast feedback and in-test guidance, which can eliminate significantly costly and slow test results. ·. analysis results, as well as eliminating the number of experiments required.

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By connecting a conveyor to the robot, which changes the concentrate cells at suitable times, it is possible to! An automated machine for long, multi-stage experiments is easily provided. Such tests include, for example, different sets of collectors, in which concentrates to be foamed with different doses of collector chemicals are taken as separate products. This makes it possible to carry out complete experiments with a robot.

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Claims (3)

1. Flotation method, in which slag in a flotation cell is supplied with gas, enrichment slag foam is peeled from the surface, the surface height of the cell is observed and the water is added so that the surface height is kept constant, characterized in that the dry weight of the enrichment slag is defined by the following formula Mk = (Pk! '0) (Mtot - Mh 2 O), in which pk = the estimated density of the enrichment solid or the actual density obtained in a previous test Mtot = the total weight of the enrichment slag Mj-i20 = the weight of the amount of water (g) = the enrichment slag volume ( ml) 2. A method according to claim 1, characterized in that a sample of the enrichment slag is also taken and a chemical analysis thereof is performed. 3. Flotation plant with a flotation cell for slag, a gas supply plant, a supply to the cell, a plant for peeling enrichment slag foam from the surface, a: "a plant for observing the surface height of the cell and a plant for water addition". that the height of the surface is kept constant, characterized in that the plant further comprises ': ": means for determining the dry weight of the enrichment slag having the following formula: :: Mk = (pk / (Pk -1)) (Mtot - Mh20)>" which:': 25 hp = the estimated density of the enrichment solid or the actual density obtained in a previous test Mtot = the total weight of the enrichment slag Mfj20 = the weight of the estimated amount of water (g) = the enrichment slag volume (ml). • · · «··· ♦ •« «• · • · ·· · 11