JPS60193556A - Flotation method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an improved flotation process and apparatus thereof, and more particularly to an improved flotation process and apparatus for improving the purity or grade of the f1 primary beneficiation produced from nine froths originating from a flotation machine. Regarding the device.

BACKGROUND OF THE INVENTION The use of conventional flotation machines to separate various minerals by a process known as friend flotation is well known. The minerals to be treated by flotation are finely ground and prepared into a water-containing slurry. Various reagents are then added to aid in flotation of the desired species from the slurry. The slurry is then processed through one or more flotation machines (hereinafter referred to as flotation machines).
sent to.

Most flotation machines used in commercial plants are mechanically vented, with vigorous agitation in a stirred tank to mix the gas bubbles and particles.

Air is introduced into the peripheral area of the impeller through the tank of the hollow shaft.

Floating particles attach to the foam and rise to its surface, where a layer of foam is formed. The foam containing valuable minerals is removed from the flotation machine, separated from the pulp or slurry containing all the waste particles.

Other configurations of flotation machines have been used in which the gas is introduced through fine holes or porous media in tubes at the bottom of the flotation machine. Furthermore, there are also methods in which the gas is mixed with the slurry flow or the entire gas is injected into the slurry solution.

In conventional flotation ores with nearly vertical sidewalls, the operating flotation machine is filled with foam from a special mineral and liquid mixture (referred to as pulp), which is vented due to the flotation machine's construction and method of operation. It reaches the height where it touches the top of the valve. The height of the foam at the top of the nokurupu is hereinafter referred to as the "normal foam height". The main volume of the flotation machine is above the foam source, which is generally a rotating impeller.

In this specification, the horizontal cross-sectional area of the body of the flotation machine refers to the total area mentioned.

Problems to be Solved by the Invention A problem with all of the above types of flotation machines is that particles of unwanted slurry are trapped in the foam.

Where bubbles are formed on the surface of a liquid slurry, the floating bubbles adhere directly to the surface of the bubbles, and the surfaces of the liquid and solid particles in which the gas and solid particles of the bubbles are suspended coexist with each other. contains the particles to be removed that form a linear contact area.

However, the liquid in the form of a thin film between each bubble has a slurry contained within the layer of bubbles. Since the waste solids are contained at roughly the same average concentration as in the liquid in the flotation machine itself, waste gangue is avoided to enter the foam along with the valuable particles destined for suspension. It will not be possible to do so. The collection and scavenging of these unwanted gangue particles results in a reduction in the grade or purity of the flotation product or beneficiation.

Purity may be improved if the bubble beneficiation is continued in the next flotation process, but the added cost and complexity of the plant will increase the financial loss compared to the reprocessing flotation machine. becomes.

In view of the above-mentioned problems, the present invention provides an improved method for removing foam and trapped particles from flotation machines, which eliminates the above-mentioned drawbacks in a simple and efficient manner and at least provides the public with a useful option. The purpose is to provide a method.

Means for Solving All Problems Accordingly, in order to achieve the above object, the present invention solves the above problems by using a flotation machine having a foam source and a blister layer to collect foam from pulp. A method for removing particles from the flotation machine, the method comprising: reducing the horizontal cross-sectional area of the flotation machine from the body of the flotation machine to the level of the fluffing layer; The step consists of operating the flotation machine so that the height of the foam from the pulp-foam interface to the foam layer is greater than the "normal foam height" as defined above. .

Preferably, in the flotation machine, the height of the foam from the pulp-foam interface to the blister layer is such that the horizontal cross-sectional area of the main body of the flotation machine is equal to the above-mentioned normal foam height. The horizontal cross-sectional area of the flotation machine at the level of the broiling layer is multiplied by the horizontal cross-sectional area of the flotation machine.

In an embodiment of the invention, the walls of the flotation machine converge in the form of a hood up to a central chimney having substantially vertical walls, with the blister layer located at a predetermined height of the chimney. The flotation machine is operated such that the interface between the pulp and the foam is located within the chimney or at a slightly lower level than the joint between the chimney and the converging 7-door.

Further, preferably, the frothing layer and the bubble generation source are arranged such that the path lengths of the six bubbles from the generation source to the layer are approximately the same, so that the bubbles overflowing the layer have uniform properties. Positioned.

EXAMPLES Hereinafter, the ore flotation method according to the present invention will be explained with reference to all the drawings.

FIG. 1 is a vertical sectional view showing an embodiment of a flotation machine applied to the flotation method according to the present invention.

The dimensions of the flotation machine in FIG. 1 can be chosen appropriately. A central impeller designated by the reference numeral 20 in the flotation machine (hereinafter abbreviated as flotation machine) serves as a source for agitating the noise contained in the flotation machine and generating small bubbles. The impeller 2
o is rotated by a hollow shaft 21 via a vertical lifting body 8. A slurry of suspended solids enters and exits the flotation machine through any combination of pipes and valves (not shown).

Fine bubbles of gas collide with the mineral particles and lift them upward onto the surface of the liquid slurry. Normally, the foam will form completely on the liquid pulp and the foam will flow from the well-placed hole edge or overflow layer into the overflow trough or open channel to the next step.

However, in the method according to the invention, the foam enters a hood or cover 2 placed on top of the liquid slurry and is directed by the hood to the base of a lifting shaft or "chimney" 4 located in the center of the hood. nru.

The hood has upwardly directed and inwardly converging side walls such that the horizontal cross-sectional area of the flotation machine is reduced.

The pulp-foam interface level of the flotation machine is determined by a suitable combination of valves or weirs, and the foam layer is raised to the height of the shaft 4.
The height of the lift shaft 4 is controlled so that it substantially coincides with the bottom 8 of the lift shaft 4 in the extended state.

Although it has been found to be most efficient to bring the pulp and foam interface to the bottom of the lifting shaft or chimney 4, the method according to the invention This is also done with the pulp-foam interface being higher only if the chimney is higher than the ink height up to +4. Furthermore, if the above device is operated with the pulp-foam interface set at a position as low as the bottom of the chimney, a layer of foam will be packed in, which will cause deterioration of the foam. It is possible.

The cross-section of the shaft 4 perpendicular to the average direction of the bubble flow is also much narrower than the cross-section of the base of the shaft 2. Therefore,
The height at which the foam rises on the lifting height shaft is increased according to the invention relative to the same foam height in an unaltered flotation machine. In fact, it is known that the height of the bubble increases to at least the height expressed by the following formula.

It also increases by % of what is expected by the above formula.

In the past, flotation machines attempted to skim off foam at a point below the normal height of the foam layer. In contrast, in the present invention the foam is encouraged to rise to a higher level than the normal foam height before overflowing the edge or overflow layer.

When the foam enters the lifting shaft 4 of the device, it carries with it a considerable amount of slurry containing cine gangue. As the foam moves up the lift shaft, the concentration of gangue particles in the foam liquid decreases, and if the shaft is of sufficient height, the concentration of gangue particles in the pond that exits the opening at the top of the shaft will be Can be reduced to a lower value.

From the top 6 of the foam column the foam containing valuable substances overflows into a trough or open-top channel 6. The top 5 of the foam column serves as a blister layer. The foam flows through the tub or top-open, open channel 6'' up to one or both ends of the flotation machine and is discharged into a common trough 7 for transport to the next processing stage (see Figures 2 and 8). It will be done.

A further feature of the present invention is that the path length of each bubble from the point of bubble entry to the final bleed layer is approximately the same, providing consistent properties throughout the bubble and allowing accurate nucleation of the bleed layer. to obtain the desired amount of final product.

The vertical shaft 4 of the foam collector may include a vertical baffle 9 which serves to guide the foam upwards.

(See Figures 2 and 3). Although the invention has been described on the basis of a substantially rectangular foam collecting shaft 4, it is not necessary that its cross section be rectangular. The shaft cross-section may be of any shape to suit the applied flotation machine.

The main features of the invention will be described in the context of a flotation machine that is custom-made to an industrial customer. Here, the surface velocity of the gas lifting the flotation machine is typically in the range α6 m/a to 2 m/8.

The angle of the shin hood 2 with respect to the horizontal plane of the roof may be any suitable angle, but it is preferably in the range of 20 degrees to 80 degrees.

The ratio of the cross-sectional area of the foam shaft 4 to the cross-sectional area of the open bottom of the foam-collecting hood 2 may be between 99:100 and 1:100, but preferably 99:100 for best results.
to 1:5 is good.

The invention has been described as if the foam collecting hood 2 and the foam collecting shaft 4 were integral parts of the flotation machine 1. The present invention also includes a collector 7-shaft, shown in FIG. 8, inserted into the open top of a conventional flotation machine.

In this embodiment, the collection hood is arranged such that the bottom of the foam column 8 is approximately flush with the liquid surface of the flotation machine, and the bottom 10 of the foam collection hood is located at approximately the same level as the liquid surface of the flotation machine. It extends deep enough into the slurry to maintain liquid tightness so that the trapped bubbles cannot escape as a result of wave action, eg, induced by the rotation of the impeller.

Controlling the height of the top 5 of the foam collection shaft, i.e. the height of the blister layer above the average liquid level of the flotation machine, in order to precisely control the amount of gangue leaving the foam column with a certain concentration. It is desirable to be able to do so.

This can be accomplished by raising and lowering the elements of the flotation machine relative to the surface of the liquid slurry.

As an alternative to the above arrangement, the foam column 4 may be constructed using a conventional telescopic type mechanism to increase or reduce its overall height. In the column 4, one part of the shaft slides inside another shaft, but with the same cross section and area, a part of the shaft having the normal increasing height is added or subtracted. There is.

In another configuration, the foam shaft has a series of horizontal openings or slots that fit into a removable cover as shown in FIG.

With all the covers in place, the foam will rise up the shaft and overflow from the top edge 5. One or more of the covers 11 may be removed if low levels of foam removal are desired.

The foam shaft 4 may be constructed such that its walls are vertical and parallel, providing a constant cross-sectional area for the flow of foam. In addition, since the cross-sectional area of the foam increases or decreases with height, the foam tends to blow out as the foam moves up the foam collecting shaft 4, so the flow rate of the foam decreases as the height of the foam increases. Maintaining a steady flow of bubbles is desirable and can be achieved by inserting a conventionally shaped object 11 as shown in FIG. The velocity of the foam at the top of the foam collection shaft can usually be maintained at approximately the same velocity as in the column of foam toward the bottom of the shaft by reducing the flow area.

The area reducing object 11 shown in FIG. 5 may be of any suitable shape. An alternative example is shown in FIG.

An example is the cowl or deflection plate 12 used in conjunction with or alone in the flow area reducing object 1 in FIG.

In this way, the bubbles moving upward are caused to overflow in the horizontal direction of the edge 5 and directed downward into the gutter 6.

A method for improving the purity of overflowing foam (by reducing gangue) will be explained with reference to experimental examples.

The foam purifier was tested in a working flotation machine. This is inner diameter 1
It consists of a plastic tube with a diameter of 50 mm and a length of 120 m, which is connected to another tube with an internal diameter of 75 mm by means of a reduction material. A small diameter tube or column is one that is made up of a number of short sections that are screwed together to increase their length.

Flotation machines are of conventional design and have a single centrally located impeller. Air is introduced through the entire shaft of the hollow impeller. A filter for condensing the foam is built into the back of the flotation machine, and the foam is overflowed, pushed at the river edge 1, and placed into the gutter for the next treatment. The cross-sectional area of the flotation machine is 90
0■X900■, and the normal foam layer is 900@@x 6
00gg.

The flotation machine processes all low-grade sulfur raw ore.

The usual depth of the foam is 180 m, and the pulp surface is 60 m below the overflow river edge.

The column is mounted vertically on the flotation machine with the nine large diameter tubes in the lowest position so that the base of the narrow part of the column is approximately at the same level as the interface of the foam-sealed pulp. .

The bubbles rising up the pulp are collected by a large tube and forced together into the base of the column, reducing the cross-sectional flow area to 1.
The more the bubbles decrease, the more the bubbles rise. The foam overflows from the top of the column.

A sample of the foam can be removed for analysis.

Below blank tube segments are added to increase the overall height of the column. And the samples are presented at different heights.

The table below shows the height of the gangue (sulfur-free) in the foam beneficiary from the float I4 machine during normal operation and the height of the debris above the foam-pulp interface. The product from the foam column is compared to gangue.

The table shows that the percentage of collected gangue (impurities) decreases very significantly when the height of p-foaming is higher. In this particular example, if we take the normal height of the bubble of 180 cm and multiply it by the ratio of the area of the large diameter tube to the area of the small diameter tube, we get a height of 720 m. It is noted from the test results that foam heights greater than 720 tons provide substantially improved gangue formation over conventional beneficent minerals from an operating flotation machine.

ADVANTAGES OF THE INVENTION Thus, by skimming foam from the top of the flotation machine and thereby lowering the mechanical skimming device or the blister layer, the normal foam brightness is reduced. This conventional practice has been shown to be erroneous, and substantially better results can be achieved by increasing the foam height from the pulp-foam interface to the broiling layer.

[Brief explanation of drawings]

FIG. 1 shows a vertical sectional view showing an embodiment of the flotation machine used in the ore flotation method according to the present invention, FIG. 2 shows a plan view of the flotation ore shown in FIG. 1, and FIG. Figure 4 shows a schematic perspective view of the hood, chimney and weir used in the flotation machine shown in Figures 1 and 2; Figure 4 shows the opening with a removable cover for adjusting the height of the layer; Figure 8 shows a side view of the device, Figure 5 shows a schematic of the location of the inner flow area reducer, and Figure 6 shows the area reducing insert and foam directing cowl. . (Explanation of symbols) ■...Flotation machine, 2...Foam collection hood 1.8.
・Bottom part of the foam lift shaft, 4...foam collection shaft (
chimney), 5...top edge, 6...gutter (top open channel), ? ...Common gutter, 8...Screen lifter, 9.
...baffle, ti...object with a shape of decreasing area, 1
2... Deflection plate, 20... Impeller, 21... Shaft with cavity. Zufuginjoku, changed to C contentkl) 7...Common pocket hθ2 +1 °°/: 7-;y,. b6.3 Shaped object/S9.6L2...Deflection plate procedural amendment (voluntary) 1986+18611 Director of the Japan Patent Office 1, Indication of fl- Mar 1988 Patent application TS cell number 8110 2. Depart! 1? Name flotation method 3, relationship with the case of the person making the amendment
Associates Li no Dead 4, Agent Address: 1-29 Meiji Jl'l', Chuo-ku, Tokyo 104, Suiseikai Building (
1) Ji Homare applicant representative column

Claims (1)

[Scope of Claims] (1) A method for producing a flotation machine containing foaming and scalding salts, the horizontal cross-sectional area of which is reduced from the main body of the flotation machine at the level of an overflow layer. The flotation machine is characterized by a process in which the flotation machine has side walls that converge toward the top and is operated so that the machine is higher than the normal foam height. (2. The method according to claim 1, wherein the horizontal cross-sectional area of the body of the affluent is multiplied from the pulp-foam interface portion, and the flotation machine is (3) The method according to item 1, characterized in that the flotation 4 & is operated so as to be higher than the horizontal cross-sectional area divided by the horizontal cross-sectional area of
the sidewalls are abraded to a chimney having converging and generally parallel sides, the blister layer is located in the chimney, and the flotation machine is operative to position a pulp and foam interface in the chimney. What it does - What it features. (4) The method according to claim 8, wherein the height of the foam in the flushing layer from the pulp-foam interface is higher than the width of the smallest cross-sectional area in the chimney. 5. A method according to claim 1, characterized in that the side walls are converging and substantially parallel sides I1m.
and the blister layer is located in the chimney) and the flotation machine is operated to position the pulp and foam interface substantially at the base of the chimney. characterized by. (6) The method according to claim 5, wherein the height of the foam from the interface part of the pulp and foam to the layer 1 is greater than the width of the smallest cross section of the chimney. Narukotokin's characteristics. (7) The method according to claim 1, wherein the foam generation source and the blowing layer are
% The method according to claim 1, wherein the ratio of the horizontal cross-sectional area of the flotation machine at the level of the requisite layer to the horizontal cross-sectional area of the body of the flotation machine is 99: 10
0 and l:100. (9) The method according to claim 8, characterized in that the ratio is 99:100 and 1:5. Margin below