JPS6036818B2 - Method for crushing ore or coal containing metal components - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for liquid grinding of ores or coal containing metal components with chemical grinding aids to obtain increased grinding efficiency.

Wet milling of minerals, especially metal ores, is used as an intermediate step in the extraction of metals from the ores.

The method used increases the surface area of the ore by reducing its average particle size, facilitating subsequent processing steps such as flotation, pelleting, separation, or chemical treatment. Such a crushing operation is
It is carried out in a grinding mill such as a ball, bead, birch or pebble mill, the mill being determined by the degree of grinding required. Self-grinding is also used. The minerals subjected to the grinding operation according to the present invention include a wide range of solid grindable materials, especially inorganic materials including metal ores.

Metal ores that can be advantageously processed using the method of the invention include:
Ores of gold, silver, nickel, iron, copper, lead and other ores or coal that can be wet-milled normally.

Minerals that are not normally used as metal ores, but which can be advantageously processed in accordance with the present invention, include minerals that are commonly subjected to milling operations or that are rendered millable by the present invention.

Such minerals include fillers for use in resins, and fertilizers, such as Senegal rock. Other materials that can be treated include organic materials with low water solubility so that they can be ground in aqueous or solvent media, such as coal or fertilizers. The term mineral is used to include all such low solubility substances. In ore processing, an essential step is the comminution of the ore to a size such that the valuable mineral particles are exfoliated from their matrix. As an inevitable trend of lower grade ore precipitation, the amount of free metal tends to decrease and the grinding cost per ton of product also increases. This factor alone constitutes a significant amount of the total cost of extracting the metal components from the ore, and the increased energy costs have made comminution costs a significant factor in operations to recover valuable metals. The amount of destruction per unit time and the mass transfer of the crushed ore are normally controlled by the addition and removal of water to the mill.

When the mass transfer of the slurry is reduced, the mill operation is reduced by reducing the solids feed rate and/or
or by temporarily increasing the amount of water or other liquid polar medium entering the mill. Although both actions prevent the mill from being overloaded, mill efficiency is reduced. This is because under such conditions less solids are ground per unit time. Therefore, traditional tumbler mills used for wet grinding of ores are extremely inefficient in energy utilization, with waste based on the chemical bond breaking energy of the ore possibly exceeding 90% of the energy supplied to the mill. over a height of % or more.

Therefore, even a small increase of a few percent in the reduction of the size distribution of ore particles and an increase in the output of ore grinding per unit time sufficiently improves the grinding efficiency and the cost of mill operations, especially with regard to energy utilization. Grinding aids for non-organic or fossilized organic minerals must meet the following requirements: [1 - To act as a harmonized slurry-fluid modifier: i.e. to constantly reduce the slurry viscosity as the grinding aid concentration increases, especially for example in large quantities of 2 and 3 at high slurry solids contents.
It shows no tendency to increase viscosity (agglomeration effect) under certain conditions such as low concentrations of grinding aids in the presence of individual ions. [2] The grinding aid retains the slurry fluid or dispersion under high shelf life conditions.

{劫 The grinding aid is structurally stable under high rock cutting conditions.

{4} The grinding aid does not affect the surface tension, that is, the operations such as floating, pelleting, and agglomeration of the ore after grinding are not adversely affected by the grinding aid.

[5- The grinding aid must be stable to humans, non-degradable, and degradable.

t6) Grinding aids should be pharmaceutically attractive, that is, they should be cheap and easily produced.

Conventionally known ore grinding aids do not satisfy all of the above conditions.

Various chemical dispersants or surfactants, such as polysiloxanes, organosilicones, glycols, amines, graphite, or non-polar liquids, when used with ore grinding aids, strengthen the ore particles and Although it was possible to prevent agglomeration of , it did not necessarily satisfy other requirements. It is known that certain polyelectrolytes have been used in milling operations.

For example, polyacrylic acid materials have been used in dry milling of pentonite for particle size reduction (U
SP3,604,634 and 3,934,825 are representative.

) However, these known chemical agents are used to crush minerals,
It has not been used in ores, especially for the dissociation of metallic components. In the references known to the applicant, U.S. Patent No.
．． Nos. 3,950,182 and 3,252,662 are the only citations that teach the use of chemical agents that can be used in the grinding of ores for the dissociation of metal components.

In USP 3,950,182, the grinding operation is
It is carried out with ionic polysaccharides, preferably sodium carboxymethylcellulose. USP3,25
No. 2,662, milling of minerals, including metal ores, is carried out with long-chain condensed phosphates, preferably sodium tripolyphosphate. The chemical agent of the present invention used in mineral milling results in a substantial increase in the rate of particle breakage and enables the milling of dense ore slurries and satisfies the six requirements listed above.

Also, when using the grinding aid of the present invention, the production of ground ore per unit time is increased in recovery of the desired metal continuity value. The improved efficiency increase in the milling operation, i.e. in increasing the capacity of the mill, and especially in the consumption of energy per unit of output, eliminates the reduction in milling capacity commonly observed when dense slurries are milled. This is achieved in accordance with the grinding aid of the present invention. A key feature of the polyelectrolyte grinding aid of the present invention is that it does not adversely affect downstream processing operations carried out on the mineral, particularly the ore, after the mineral leaves the grinding mill. That is, for example, the selection of metal components such as copper, lead, zinc or gold in polyelectrolyte grinding aids is detrimental to processes such as froth flotation recovered from the ore with the aid of flocculants and deflocculants. not give. The polyelectrolyte grinding aids of the polyelectrolytes of the invention do not have an adverse effect on the subsequent operation of pelletizing iron ore, for example. Furthermore, the polyelectrolyte does not create downstream contamination problems when the aqueous medium is discharged, as may occur, for example, with phosphoric acid grinding aids. The present invention involves grinding non-organic or fossilized organic minerals in a liquid slurry that includes a polymeric grinding aid, the polymeric grinding aid being inherently dispersible in the liquid slurry, and With a hydrocarbon backbone and a large number of anionic side chains, the polyelectrolyte is present in an effective amount to increase grinding efficiency. The milling efficiency is greater than the 325 mesh (44 micrometer) U.S. that can be formed from a given amount of liquid and ore solids using the same energy. S.
Determined from the amount of particulate solids with substandard particle size.

Typically, as the weight percentage of ore solids in the slurry increases, the grinding efficiency of the grinding media decreases. That is, it is essential in the practice of this invention to use a sufficient amount of polyelectrolyte grinding aid to reverse the tendency for grinding efficiency to decrease as the weight percent concentration of ore solids in the slurry increases. The polyelectrolyte grinding aid used in the present invention is an inherently liquid-dispersible polyelectrolyte, which has a hydrocarbon, preferably polyethylene backbone and a number of bulbous suitable anionic groups. .

Inherently liquid dispersible means that the polyelectrolyte can be dispersed in the liquid slurry, preferably water, without the aid of an external surfactant, forming a dispersion or solution, and in which case the dispersion or Dissolved particles are meant to be smaller than colloidal size.

The polyelectrolyte grinding aid is preferably water-soluble. Suitable anionic groups of the polyelectrolyte grinding aid have a PKa of 6 or less, where PKa is the negative logarithm of the acidity constant for acidic (anionic) groups.

The anionic groups are preferably carboxylate or sulfonate groups, their precursors as anhydrides, ammonium or metal salts of acids or esters. However, when an ester group is used, the conditions of use must be sufficient to hydrolyze the ester to the acid. The number of anionic groups in the polyelectrolyte is such that when the polyelectrolyte is added to the slurry in an amount sufficient to provide a polyelectrolyte concentration of 0.06% by weight based on total mineral solids, It is sufficient to reduce the viscosity by a minimum of 10%. Low shear viscosity means Brookfield viscosity determined on a Brookfield viscometer using a #D bar at 2500 and &pm. Mineral slurry is a mineral slurry in which the minerals are ground to a particle size of 325 mesh and have a solids concentration of about 5 ml in the liquid medium.
It means 0 to 95% by weight. Preferred polyelectrolytes produce a viscosity reduction of at least 20% under such conditions, most preferably at least 40%. Insofar as this necessary viscosity reduction occurs, the polyelectrolyte used advantageously contains anionic groups in the polyelectrolyte, such that there are from 1 to 17 meq., preferably from 2 to 4 meq., of anionic groups per night of polyelectrolyte. It has a proportion of groups. Polyelectrolytes are polymers or copolymers of anionic monomers such as Q,8-ethylenically unsaturated carboxylic acids, including, for example, acrylic acid, methacrylic acid, fumaric acid, maleic acid, crotonic acid, itaconic acid, or citraconic acid. partial esters of Q,8-ethylenically unsaturated polycarboxylic acids, such as monomethyl maleate, monomethyl fumarate; Q,8-ethylene, such as N-(sulfomethyl)acrylamide or N-(sulfomethyl)methacrylamide; N-sulfalkyl derivative of system unsaturated amide; 2-sulfoethyl methacrylate or 2
- sulfoalkyl esters of Q,8-ethylenically unsaturated carboxylic acids such as sulfoethyl acrylate; or Q,8-ethylenically unsaturated aromatic sulfonic acids such as styrene sulfonic acid or vinyltoluenesulfonic acid; It is a polymer or copolymer of other sulfonated monomers.

Also included are sulfonated aliphatic monoolefinated polymers such as sulfonated polystyrene or sulfonated poly(vinyl)toluene or sulfonated polyethylene.
Such water-dispersible polymers or copolymers can be prepared by polymerization of the monomers specified above alone or by polymerization of monovinylidene aromatics such as styrene; alkyl esters of Q,8-ethyleneically unsaturated carboxylic acids such as ethyl acrylate or methyl methacrylate; such as vinyl acetate, vinyl propionate, vinyl benzoate; It will be understood that vinyl esters; vinyl chloride or vinylidene chloride are made by polymerization with ethylenically unsaturated amides such as acrylamide or methacrylate; or other vinyl monomers such as acrylonitrile or methacrylonitrile.

Polyelectrolytes of particular interest are polymers of acrylic or methacrylic acid, and also their metal salts, such as sodium polyacrylate or acrylamide/acrylic acid copolymers, which can be derived from the partial hydrolysis of polyacrylamide. be.

Of further interest are polymers of N-(sulfoalkyl)acrylamide or N-(sulfoalkyl)methacrylamide, or, for example, the sodium salt of N-(sulfomethyl)acrylamide or the sodium salt of N-(sulfomethyl)methacrylamide. be. Also of particular interest are water-soluble salts of sulfonated polystyrene or sulfonated polyvinyltoluene, where the salt is an alkali metal or ammonium salt. Of particular interest are copolymers of styrene and maleic anhydride, itaconic acid or citraconic acid, or metal salts thereof, such as the sodium salt of styrene maleic anhydride. Also of particular interest is sulfoethyl methacrylic acid or its metal salts, such as the sodium salt of sulfoethyl methacrylic acid. Among the aforementioned polymers, sodium polyacrylate and styrene maleic anhydride polymers are preferred, with sodium polyacrylate being most preferred.

Those skilled in the art will recognize that certain ethylenically unsaturated polymers, such as acrylamide, are sometimes characterized by a large or small degree of hydrolysis, ie, contain certain free carboxyl groups.

The conditions depend on the method of making the polymer, the presence or absence of other minor components in the starting monomers, storage conditions, etc.
The polymer product appears to correspond to whether the carboxyl arises from a polymer of acrylamide and acrylic acid or from hydrolysis of an amide group followed by polymerization or copolymerization of acrylamide and acrylic acid. However, grinding aid products resulting from either method are within the scope of this invention. Other additives, such as triethylamines, can be added along with the polyacrylic or methacrylic acid polymer, for example, so long as the resulting product contains about 50% or more of polyacrylic acid or methacrylic acid monomer. The polymers and copolymers described herein are commercially available in a variety of shapes and molecular weights and can be made by those skilled in the art by known methods.

Preferably, the grinding aid is between 1,000 and 60,000
It has an average molecular weight of 0, more preferably 2,000 to 20,000.

As long as the conditions indicated above are met in the selection of the particular polyelectrolyte, its molecular weight can vary over a wide range and is not a necessary requirement. The polyelectrolyte grinding aids preferred in the present invention are made by methods known in the art and do not form part of the present invention and will not be described in detail.

The milling operation of the present invention is preferably carried out in a polar liquid, most preferably an aqueous medium in which at least a sufficient amount of the grinding aid is dispersed, resulting in improved milling efficiency, but with It is possible to use a liquid medium consisting of a liquid that is not itself a solvent or dispersion, provided that the solvent or dispersion is present in the medium.

Water is the preferred medium. The concentration of ore solids in the liquid medium can vary over a wide range, but preferably operates between 40 and 95%, more preferably between 50 and 90%, particularly preferably between 70 and 88%. All percentages are by weight of solids in the slurry. grinding efficiency,
Properties that are unique to each ore include, for example, the amount of grinding aid used to increase the rate and type of ore particle breakage, the ore classification described individually as sorting, and the distribution function of the grinding. It varies depending on certain factors. The selection function, which means, for example, the suitability with which particles of a particular size are crushed per unit time, is influenced by factors that change the suitability of particle breakage. Factors such as mill type, slurry volume, size and number of grinding media (e.g. balls or grains), raw ore particle size, mill speed or ore properties all influence the suitability for successful particle breakage. give. Properties that are unique to each ore affect the distribution function, ie, the size distribution and number of fragments into which the particles break up when they are broken. Measurement of the number and size distribution of fragments after grinding allows calculation of the effectiveness of the added grinding aid, which indicates the sorting and distribution function indicating its effectiveness. The liquid slurry preferably contains a grinding medium, where balls, beads, combs, or pebbles are used in large ore grinding mills.

A medium is of sufficient size if it does not contribute to an increase in the unique particles of the slurry. Thus, with these considerations in mind, the type of mill differs from a mill in which paint pigments are ground to an extreme fineness using granular grinding media. Generally, the effective amount of grinding aids used to increase the speed of ore grinding is
Approximately 0 active polyelectrolytes based on dry weight of ore present
．． It may be as low as 0.002% by weight.

The maximum amount of grinding aid used is usually limited by pharmaceutical factors. That is, the chemical grinding aid is expensive. Preferably, the grinding aid of the present invention contains active polyelectrolyte 0
．． 003 to 0.0% by weight, more preferably 0.01 to
0.04% (0.03-0.8 9/tam ore, preferably 0.1-0.4 9/tam ore) is used. In batch operations, grinding times of 5 to 10 minutes or more are usually sufficient to provide increased grind fineness when using grinding aids such as those shown below.

Increased production and/or
Alternatively, at a given production rate, an increase in the fineness of the grind is easily achieved. However, in a continuous closed circulation milling operation, the ore to be milled in the mill is continuously milled until the desired degree of fineness is obtained, and the actual milling time per unit of ore is calculated on the basis of the average residence time. . This will vary depending on the type of ore used and the amount of grinding required to meet size distribution requirements. For example, in iron ore, grinding continues until the particle size is less than 325 mesh (US standard), sometimes less than 500 mesh. Again, those skilled in the art of milling can determine the required milling time. The increase in crushing force is determined by measuring the weight and size distribution of the fragments obtained per unit time. An increase in the amount of grinding or the fineness of the grind, as determined by measuring the particle size produced per unit of grinding time, means that more efficient grinding has taken place. To account for the increased grinding speeds achieved in other methods, if a grinding viscosity of, for example, 50,00 specific ps is desired and the milled ore slurry is 68% solids, then the grinding conditions High solids density slurries of, for example, 72% solids can be ground by the use of a grinding aid without a change in grinding aid.
Increasing the throughput or the fineness of the grind by even 1-2% is preferred as they represent significant savings in unit energy costs. According to the method of the present invention, experimental data shows that the increase in grinding production of 1-20% and/or the fineness of grinding for a particular ore particle size under constant production is shown below. Can be achieved according to the use of grinding. In determining the usefulness of a particular agent as a grinding aid,
Various chemicals are initially screened to determine the ability of a particular chemical to increase the flowability of the finely divided ore.

These agents, commonly found to reduce the viscosity of ores (ground to a particle size of 325 mesh and having a solids concentration of 50-95% by weight) by 20-25% or more, are usually then treated as grinding aids. was found to be very effective.

Generally, the greater the reduction in slurry viscosity, the greater the increase in grinding. However, the viscosity value is not sufficient by itself to indicate the increase in the degree of grinding obtained. this is,
The result is determined by the actual grinding attempt. In carrying out actual grinding tests, ore samples are ground in a typical ball mill using pure water as the liquid phase. After each milling operation for a predetermined time, the product size distribution is determined by wet screening. Adequate operation requires different grinding periods and slurry
Made in concentration. Changes in weight and size of debris can be determined. The operation was then repeated with a grinding aid included in the slurry and the same determination was made. Changes in debris size and weight compared to the control run indicate the effect of the grinding aid. The following examples exist to demonstrate the invention.

The ore slurry percentage is based on the weight of solids present in the slurry to be treated. 9 claws / based on the actual number of 9 claws of crushed ore per night. EXAMPLES Various chemical agents were screened to determine their effectiveness in reducing the viscosity of finely ground ore.

In such operations, the crushed ore is mixed with sufficient quantities to form a viscous slurry, typically between 100,000 and 150,00 ps. The viscosity of the slurry is determined by the rover and helipath stands.
The helipath moves a slowly vertically rotating bar (5 rpm) so that the bar continuously faces a flat IJ. A diluted solution of the test agent was then added to each slurry in increments of lcc. The viscosity change was plotted as a function of treatment concentration and the results were compared to the untreated slurry. In each run, the viscosity of the slurry treated with various concentrations of sodium polyacrylate and copolymer of polyacrylate and acrylamide (metal/ta) was found to be reduced compared to the control sample.

Table l pot stone aid
Decreased slurry viscosity Taconite (a) Na polyacrylate 0.2
40 Taconite (b) Na polyacrylate 31 Copper (c)

42-68(a) Gold
〃 75 iron (e)
57 copper (f)

32-47(d) Copper (g)
68k gold

58-65(d) Iron(e) (h quecrylamide 25 mol 50-55(d)
% and acrylic acid 75 mol% copolymer Na salt iron (b) 〃 〃
42 copper (f)
27-47(d)
Copper ■ 〃 〃 68
Money
70-75(d)(a) Du
Eleth〉(Sherm false n) (c) Duval (d) Average of several samples (e) Hanna (f) Morenci (g) Kinkman (crying 75 mol% carvone) Substantial reduction in viscosity of polyacrylamide hydrolyzed to acid
:1 and other polyacrylate-acrylamide in molar ratios of 1:3.

Ore slurry in ore crushing operations at the same or lower concentration
Subsequent evaluation of these agents, which substantially reduce the viscosity of , shows a surprising and significant increase in grinding power. Example 2 The method of Example 1 and styrene/maleic anhydride copolymer (SMA), poly N-(sulfomethyl)acrylamide (Mannich % reacted indicating the extent to which useful amide groups are reacted), sulfonated polystyrene, poly( In additional such operations utilizing materials such as 2-sulfoethyl) methacrylate and its copolymer with acrylamide, the viscosity of the polyelectrolyte-treated slurry was found to be reduced compared to control samples. .

Such data is reported in Table Row V below.
Table 0 Ore Materials / 9 Taconite (a) A O. 2 23 taconite (b) 〃 〃 50 gold
〃 〃 19 Iron B I0
60 copper (d) 〃 〃 30 copper (e)
〃 〃 43 iron (b) 〃
〃 57A = Disodium salt of styrene/maleic anhydride copolymer (molecular weight 20001:1 molar ratio) B = Disodium salt of styrene/maleic anhydride copolymer (molecular weight 20002:1 molar ratio) {a} Erebes { b} Shellman [c-Hannah [d} Morenci'e}
Kingman Table M Clasp Auxiliary Agent Rumored Slurry - Increase in Viscosity % Taconite (a) A O. 2
25 Taconite (b) C 58
Copper c 〃 〃 40K gold 〃
〃 59 iron (e) 〃 〃 27 iron (e
) B 29 copper (f)
A 16 copper (f) B
14 copper (mother A ・8 copper (
9 B 26 Gold A 〃 9o Gold B 〃 92 Iron (b) A 42 Iron (b)
B 〃 54 copper (f)
C 32K gold C
87 [a-Erebes {b} Shellman (c) Duval {e) Hanna {f} Moresin (g) Kingman A = Poly N-(sulfomethyl)acrylamide (25 mol% of amide groups are substituted with sulfomethyl) B =
Poly N-(sulfomethyl)acrylamide (75 mol% of the amide groups are substituted with sulfomethyl)C=polyN-(sulfomethyl)acrylamide (10 of the amide groups
(0 mol% is substituted with sulfomethyl) table w ore auxiliary agent female/ta
Increase in Slurry Particle Size % Taconite (a) Low Molecular Weight Sulfonated Poly 3
2 Styrene Na salt (100 mo/% sulfonation) Kindo (b)
42-43 (C) Iron (d)
〃 〃
33 copper (e) 〃 〃
24 iron (f) 〃
〃46 ore
Auxiliary agent Myo/wo Slurry particle size increase% iron (f)
1.0 38 copper (e)
58 iron (
f)
79 (a) Erebes (W Duval (c) range of several samples (of Hanna) (e) Morenci (f
) Shellman Table V Ore Auxiliary Agent Similar/9 Slurry Viscosity Increase % Taconite etc.) A 02
23 taconite also) B 30 taconite) A 50 Taconite) B 69 Copper (c) A 36-48d) Copper (c) B 18 gold
A 〃 33 gold B 〃 35 uranium A 41 uranium B 28 iron (e)
A 〃 13 iron (e) B
〃 33 iron (f) A 〃
38 iron (f) B 〃 3
7K gold A 〃 98K B
〃 95 A = Sodium salt of poly(2-sulfoethyl methacrylate) B = Copolymer of 80 mol% sodium salt of 2-sulfomethyl methacrylate and 20 mol% acrylamide (a} Erebes'b' Shellman {c} Duval (d} Sample Range of Values {c) Hanna'f) Morenci Substantial viscosity reductions were also obtained at other concentrations and with other homopolymers and copolymers.

Subsequent evaluation of these chemicals to substantially reduce the viscosity of ore slurries in ore milling operations at the same or lower concentrations showed a surprising and significant increase in milling capacity. EXAMPLE 3 A ball mill having a 19.5 inch internal diameter and approximately 20 mm length, operating at approximately 6 mm and having 11 hard inch steel balls was utilized for milling experiments with various ores and was used in accordance with the present invention. The effectiveness of using grinding aids was determined.

In such operations, the ore is crushed until it passes through a 10 US mesh screen and then mixed with appropriate water in the mill to form a slurry of the desired consistency. When the desired slurry concentration is formed, the mill is closed and operated for various grinding periods, then the resulting ground ore slurry is removed and 32
5U. S. The amount of particles passing through the mesh screen was determined. The trial was repeated at the same concentration and grinding time with various grinding aids added to the aqueous slurry before grinding. table
A=sodium polyacrylate, molecular weight 5000-1
0000 (a) % increase compared to control (b) = Mesabi Range Ore, (c) =
Duval ore supply = 500 mesh or less 9% (d)
= Duyuval ore Crude feed = 5% below 500 mesh (
e) = Morenci Ore The above data shows that at a constant comparative milling time, the weight % passing through 325 mesh is high in all instances using milling aids.

A significant and surprising increase in grinding power is achieved even with small amounts of grinding agent (operation No. 5 grinding aid increases by 2.6% at 9/ta of 0.15 or 0.015 wt%), compared to This is observed even when using relatively short milling times (Operation No. 3% increase after 30 minutes of milling at 0.05% milling aid or 0.005% by weight). A dramatic and surprising increase in grinding power is shown at high concentrations but clearly economical amounts of grinding aids. A 10-17% increase in the number and size of minus-325 mesh fragments is 0.02-0.05 wt.
Obtained in amounts ranging from 2 to 0.5 9/t. Measurements at other particle sizes and ranges also show increased significance of the same. Example 4 In the procedure as shown in Example 3, additional grinding aids were evaluated and the results are shown in Table X.

Table Skin * % increase compared to control ** Na salt of styrene/maleic anhydride polymer (molecular weight 2000 styrene to maleic anhydride molar ratio: 1)
The above data shows that for a constant comparative grinding time, 325
The weight percent passing through the mesh is higher in instances where grinding aids are used.

Significant increases in grinding power occur even when low concentrations of grinding aids and relatively short grinding times are utilized (operation no.
In 2, the grinding aid is 9/ta of 0.5 or 0.05% by weight.
A dramatic and surprising increase in the grinding power observed (for 30 minutes) is shown when longer grinding times are used.
More than a 10% increase in the amount of ore passing through 325 mesh was obtained after 60 minutes of milling.

Similar significant increases were obtained with other particle size and range measurements.

Other grinding aids of the present invention have also been found effective in increasing the grinding power of these and other ore sources. table
Plate * = % increase compared to control ** = Gichi Funun Substituted Mori Sounta) Acrylamide, 100% of the amide groups are sulfo and stock = Erebes Ore The above data is 325 mesh at a constant comparative grinding time The weight percent passing through is high in all cases where grinding aids are used.

The significant and surprising increase in the grinding power is shown even at low concentrations of grinding aid (0.8 female/grinding aid in operation no. 6).
i.e. 4.3% increase at 0.08 wt%), is observed even when a relatively short milling time is utilized (15 min), and after 30 min of milling at the same wt% milling time approximately An increase of 12% is observed (operation No. 8). A very significant increase of 20% was obtained after a milling time of 45 minutes.

Other particle size and range measurements showed similar significant increases. The above data show that for a given comparative milling time, the weight percent passing through 325 mesh is high in all instances where milling aids are used.

The significant and surprising increase in grinding power is relatively short even at low concentrations of grinding aid (9/ta of grinding aid 0.2 or 0.02% by weight in operations No. 4 and 6). Even when milling times are utilized (16 and 26 minutes), this is acceptable. Similar significant increases are also shown for other particle sizes and ranges. Table × *= Increase compared to control ** = % Na salt of 100 moles/100 moles of round lephonated copolymer of vinyltoluene and styrene (3:1 molar ratio of vinyltoluene to styrene) ***; 76% Duval Steel Ore Table x A = Sulfoethyl methacrylate (SEM)/acrylamide copolymer SEM to acrylamide molar ratio 4:1
The above data increases the amount of ore crushed per unit time,
All examples demonstrate the effectiveness of the present invention with a higher weight percentage of ore particles passing through 325 mesh.

Significant and surprising increases in grinding power were obtained even when relatively low concentrations of grinding aid, such as 1.0 mm/kg, were used.

Other particle sizes and ranges also show similar significant increases. Other grinding aids of the present invention have been found to be effective in increasing grinding power with these and other ores. Example 5 In another method carried out according to the method of Example 3,
A homopolymer of sulfoethyl methacrylate was evaluated as a grinding aid in a 72 weight slurry of morenci ore.

The grinding time was 40 minutes. As a control, the weight of ore passing through 325 mesh (U.S. standard) was 5% by weight.
Met. For the test samples treated with 16 and 80 of the 9/T ore, 56 and 62.5 weight percent of the crushed ore passed through the 325 mesh screen. Compared to the control, the grinding aid increases the grinding force and increases the amount of ground material passing through 325 mesh.
12 and 25% increases compared to control, respectively.
In order to further clarify the effectiveness of the chemical grinding aid of the present invention on an industrial scale, reference is made to the graphs shown in the drawings. Attempts were made with taconite ore in an industrial scale overflow discharge mill, where the ore was ground on a continuous circulation basis.
The vertical axis of the graph shows the production of ore produced by the mill in tons per hour with a constant (±1%) particle size of 35 mesh (US standard) or less. There is. The horizontal axis indicates the weight percentage of the solids present in the slurry. Curve A shows the data obtained by carrying out the milling operation without the addition of chemical milling aids.

Without the addition of chemical aids, the optimum range of ground ore in an aqueous slurry is obtained at 80-82% solids in the slurry. As the proportion of solids in the slurry is increased, it is necessary to reduce the production of crushed ore in order to maintain a constant proportion of products below 35 mesh. That is, at 86% solids, it is about 400 tons per hour, while at a solids concentration of about 80-82% it is about 410 tons per hour. Curve B uses a chemical grinding aid, sodium polyacrylate, at 0.13 pounds per ton of dry ore.
The results of the milling operation are shown when an amount of 0.065 9/pm) is added continuously to the slurry.

The results were initially quite as expected, with the addition of the grinding aid at a solids concentration of 80-82% in the slurry compared to Operation A where no grinding aid was added to the slurry. resulting in a slight increase in production. What is not at all obvious, however, is that when the fixed concentration of the slurry is increased to about 82%, a sharp increase in production can result. That is, at 84% mesh content, the production rate was increased to about 420 mesh per hour to maintain the same percentage of 35 mesh or less in the product. 8
At 6%, about 450 tons per hour was reached, representing an increase of about 10% over the 82% solids content.

Curve C shows that increasing the amount of sodium polyacrylate grinding aid further increases the yield especially at slurry solids concentrations of about 82%.

An increase in the solids concentration of the slurry of about 86% is expected to cause a gradual averaging of its production, and a subsequent drop at solids contents of 90% and above.

The practical attempt was not made to an extent of more than about 86% to avoid hypothetically significant problems in the operation of the mill caused by a phenomenon well known to those skilled in the art, namely entanglement of the rods. . In the grinding of taconite in the Ham mill, the addition of sodium polyacrylate grinding aid in this industrial scale trial was
Not only does it prevent a decrease in production at a solid concentration of % or more, but it also
It is shown in the figures that increasing the solids concentration of the slurry actually results in increased production.

This effect is not completely obvious, resulting in either a solids concentration of the slurry at a relatively constant production rate, or a small increase in production if an uneconomically large amount of grinding aid is added to the slurry. This is surprising even in light of previous experiments showing how effective it is. In batch tests on a laboratory scale, taconite ore was ground in a mill according to the procedure of Example 3, and sodium polyacrylate was evaluated as a grinding aid.

The results are shown graphically. Table Illusion (1) All operations are 0% sodium silicate per 12 ores.
Including 5 guys.

The foregoing data demonstrate the effect of the sodium polyacrylate grinding agent in Runs 4 and 5 on the reduction in grind fineness in Runs 1-3 that were performed without the addition of grinding aid. As expected, the fineness of the grind in the ground ore decreases in runs 1-3 as the solids concentration increases in the aqueous slurry. However, the addition of a relatively high concentration of grinding aid of only 0.19 9/l at a relatively high weight percent solids concentration results in an increase in the fineness of the grind. A further increase in grind fineness is obtained in operation 5 by increasing the grinding additive addition to 0.28 9/ta ore.
In another laboratory-scale batch test conducted according to the procedure set forth in Example 3, the presence of a dispersant (sodium silicate) in the slurry was evaluated as a grinding aid.

The results are shown in a top plate. Table Dish (1) All operations are performed with 0.0% sodium silicate per 19 ore.
Contains 5 females.

In each of operations 1 to 4, 9 of 0.5 for copper ore
The use of sodium silicate as a dispersant in amounts of 1/2 does not overcome the expected reduction in the fineness of the ore particles after 30 minutes of grinding, which has been experimented in purely aqueous systems. In runs 1-3, the fineness of the grind decreased from 960 mm to 818 mm as the solids content in the slurry increased. The addition of a sodium polyacrylate grinding aid in operation prevents its reduction and results in a substantial improvement in the fineness of the grind.

[Brief explanation of the drawing]

The figure is a graph showing an example of grinding taconite in a continuous mill on an industrial scale.

Claims (1)

[Claims] 1. A method for pulverizing ore or coal containing metal components, comprising the step of pulverizing the mineral in a liquid slurry containing a polymeric grinding aid, the grinding aid being present in the liquid slurry. and wherein the anionic polyelectrolyte has a hydrocarbon backbone and a large number of side chain anionic groups, and the polyelectrolyte is dispersed in A method characterized in that a sufficient effect amount exists. 2. The method of claim 1, wherein the slurry has a solids concentration of 40 to 95% by weight solids in the slurry. 3. The method of claim 2, wherein the solid content concentration in the slurry is 50-90%. 4 The polymeric grinding aid contains 0.002 to 0.00% of the active polyelectrolyte based on the dry weight of the mineral or coal present.
4. The method of claim 1, 2 or 3, wherein the method is present in the range of 0.08% by weight. 5 The polyelectrolyte contains 0.01 to 0.04% by weight of active polyelectrolyte based on the dry weight of the mineral or coal present.
The method of claim 4 falling within the scope of. 6. The method of any one of claims 1 to 5, wherein the anionic groups in the polyelectrolyte range from 1 to 17 milliequivalents of anionic groups per gram of polyelectrolyte. 7. The method of claim 6, wherein the proportion of anionic groups in the polyelectrolyte ranges from 2 to 14 milliequivalents of anionic groups per gram of polyelectrolyte. 8. The method of any one of claims 1-7, wherein the anionic group side chain on the hydrocarbon has a pKa of about 6 or less. 9. The method of claim 8, wherein the anionic group is a carboxylate or sulfonate. 10. The method of any one of claims 1 to 9, wherein the polyelectrolyte has a polyethylene backbone. 11 Claims 1 to 1, wherein the polyelectrolyte is a polymer or copolymer of water-dispersible anionic monomers.
One of 0 methods. 12 The polyelectrolyte is inherently water-dispersible α,
Polymers of β-ethylenically unsaturated carboxylic acids, polymers of partial esters of α,β-ethylenically unsaturated polycarboxylic acids, polymers of N-sulfoalkyl derivatives of α,β-ethylenically unsaturated amides, α , a polymer of sulfoalkyl ester of β-ethylenically unsaturated carboxylic acid, a polymer of α,β-ethylenically unsaturated aromatic sulfonic acid; a combination of at least one of the aforementioned monomers and another ethylenically unsaturated monomer. The method according to claim 10 or 11, wherein the polymer is a sulfonated monovinylidene aromatic polymer; or a sulfonated aliphatic monoolefin polymer. 13. The method according to claim 12, wherein the polyelectrolyte comprises a water-soluble salt of a homopolymer of N-(sulfoalkyl)acrylamide or N-(sulfoalkyl)methacrylamide, or a copolymer of the same and an ethylenically unsaturated monomer. . 14. The method of claim 13, wherein the salt is an alkali metal salt or ammonium salt of N-(sulfomethyl)acrylamide or methacrylamide. 15. The polyelectrolyte is a water-soluble copolymer of sulfonated polystyrene or sulfonated polyvinyltoluene, or either of them and other ethylenically unsaturated monomers, and the salt thereof is an alkali metal salt. 12 ways. 16. The method of claim 12, wherein the polyelectrolyte is polyacrylic acid, polymethacrylic acid, sodium polyacrylate or sodium polymethacrylate. 17. The method of claim 12, wherein the polyelectrolyte comprises a water-soluble salt of a copolymer of styrene and maleic anhydride, or a sodium salt of a copolymer of styrene/maleic anhydride. 18 The polyelectrolyte consists of a water-soluble salt of a polymer of sulfoethyl methacrylic acid or a copolymer thereof with other ethylenically unsaturated monomers, and the salt of the acid is an alkali metal or ammonium salt. Claim 12 Method. 19. The method of any one of claims 1 to 18, wherein the polyelectrolyte is a polymer or copolymer having a molecular weight in the range of 200 to 100,000.