RU2493274C2 - Method for extraction of free gold from alluvial and ores and device for this method implementation (versions) - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: gold-bearing pulp from alluvial and ores is prepared, absorbent based on liquid hydrocarbons is used. Density of this absorbent is lower than density of the pulp. Then pulp contacts absorbent, during this process free gold transfers from pulp to absorbent. Free gold is extracted from absorbent by absorbent filtration in filter press. Volumetric contact of pulp with absorbent is performed due to pulp filtration in downward direction through at least one layer of absorbent, at that used absorbent has oxidation-reduction potential (Eh) not less than +1400 mV and is characterised by adhesion value to free gold not less than 40 Pa. Process efficiency of production plant for filtration-absorption extraction of gold from gold-bearing pulp is 800-1000 m³/day.

EFFECT: improving extraction efficiency of free gold of small, thin, pulverescent and disperse classes from alluvial and ores.

16 cl, 1 dwg, 5 tbl, 5 ex

Description

FIELD OF TECHNOLOGY

The invention relates to methods and devices for extracting free gold from placers and ores.

Also, the present invention relates to methods and devices for the enrichment of free gold of large, medium, small, thin, dusty and dispersed classes of fineness.

Also, the present invention can be used in prospecting for placer gold, especially where free gold is dominated by small, thin, silty and dispersed fineness classes.

The present invention also relates to methods and devices for extracting free gold from natural and man-made placers and ores with a low content of free gold, namely from waste dumps, overburden quarries, as well as from hard-to-reach clay placers.

The present invention also relates to methods and devices for extracting free gold from gold-bearing sludge - waste from the processing of iron ore, bauxite, manganese, potassium salts, titanium-zirconium placers.

BACKGROUND

In recent decades, in gold-mining countries, in connection with the depletion of reserves of easy-to-concentrate placers with large gold, placers are used that primarily contain small, thin, dusty and dispersed grains of free gold.

Re-developed man-made placers and ores with the content of fine and fine free gold.

Free gold is being extracted from new types of deposits - gold-bearing weathering crusts, ancient alluvial placers with prevailing gold reserves of small, thin, dusty and dispersed classes.

Table 1 shows the classification of free gold by size classes.

Table 1 Class name Size class, mm Large -2 + 0.5 Average -0.5 + 0.25 Shallow -0.25 + 0.1 Thin -0.1- + 0.05 Dusty -0.05 + 0.01 Dispersed -0.01

In the zone of hypergenesis, gold is in a native state (free gold), rarely included in sulfides (pyrite, sphalerite, antimony). In addition to free gold, there are refractory forms of gold, the so-called "gold in a shirt" - coated with thin films of hydroxides of iron, manganese, clay minerals.

Deposits of free gold, in the composition of which fine, fine, dusty and dispersed gold predominates, are referred to refractory deposits.

Known gravitational methods of enrichment for them are unacceptable, since most of the reserves of free gold will be carried to the tailings of enrichment.

Therefore, the urgent task is to develop new methods and devices for prospecting and exploration of various types of refractory deposits.

Also an urgent task is to increase the efficiency of extraction of free gold of small, thin, dusty and dispersed classes from natural and man-made placers and ores.

Also an urgent task is the industrial extraction of free gold from refractory deposits.

Also an urgent task is to extract free gold from poor alluvial deposits, which mainly contain small, thin and dispersed classes of gold, for example, poor deposits include used alluvial deposits and ores, for example, tailings, sludges that contain free gold of small, thin, dusty and dispersed classes, gold-bearing sludges can also be referred to poor deposits, namely, sludges from wastes from the production of iron ore, bauxite, manganese, potassium salts, titanium-zirconium placers.

The selective extraction of free gold by surfaces containing fat has been known since the 5th century BC. To extract free gold from sludge, feathers moistened with grease were used, to which particles of free gold, gold, were selectively adhered. In a known manner, free gold of small, thin, dusty and dispersed classes was not extracted.

A further improvement in the method for extracting free gold from placers and ores was oil pulp flotation for the selective extraction of free gold.

Oil flotation was developed in England in 1860. According to the oil flotation method, finely ground gold ore was mixed in a 6: 1 ratio with mineral oil, then water was added and the oily sulfides floated to the surface. Grains of rock minerals settled on the bottom of the flotation machine, and a mineralized layer formed on the surface.

Subsequently, oil flotation was improved by introducing a gas component to facilitate the flooding of oily sulfides (gas oil flotation was developed in Germany in 1877), as well as sulfuric acid, which enhances the selective wetting of sulfides with oil. The latter method was developed in the USA.

The oil flotation method is based on the good wettability of free gold and other ore minerals, mineral and vegetable oils, fats, i.e. high molecular weight substances.

Oil-gas flotation required the use of a large consumption of mineral oil, which made the process of extracting free gold expensive and ineffective. For poor alluvial deposits and ores, which mainly contain free dusty and dispersed classes of gold, oil flotation is ineffective due to the low weight of light gold to the surface of the air bubble. Oil and gas flotation is also ineffective for placers and ores with free and large gold grades due to the significant weight of gold grains. Oil-gas flotation flots well free gold of small and thin classes.

At the present stage, 2/3 of free gold at the processing plants is mined using the flotation method. Modern methods for the extraction of free gold based on the flotation method are based on the selective wettability of free gold and rock minerals by collector reagents and depressant reagents. Collector reagents increase the adhesion of free gold to air bubbles. Dipressant reagents increase the hydrophilicity of rock minerals. Foaming agents create a large amount of air bubbles in the pulp volume, to which free gold with an oil shell is adsorbed. Zolotin attached to an air bubble rises to the surface (floats) and is selected in the form of mineral foam for the subsequent extraction of free gold.

The bond strength of the gold with the air bubble depends on the diameter of the air bubble, the size of the gold, the density of the liquid in the flotation machine.

Float only those gold that adhere to the air bubble in a very short time - 4-8 ms. In this case, the coarseness of the zolotins, the size of the air bubbles, the amount of reagents, and also the duration of the contact of the air bubble with gold, which increases with increasing coarseness of the zolins, play a role.

The disadvantages of the flotation method are:

- floatability of free gold of predominantly thin class (-0.1 mm);

- high consumption of reagents that are spent on dispersed rock minerals;

- the need for preliminary deslaming;

- the use of acids to enhance adsorption;

- the costs associated with foaming (aeration);

- low probability of catching gold by air bubble;

- the duration of the method of extracting free gold associated with the sedimentation of the foam;

- low extraction efficiency of free gold of large, medium, silty and dispersed classes;

- low efficiency of extraction of free gold from poor placers and ores, which mainly contain thin, dusty and dispersed classes of gold;

- low efficiency of extraction of free gold from refractory deposits.

The closest solution to the proposed invention is a method for extracting free gold and a device for its implementation (patent application RU No. 2001131692 A, IPC C22B 11/00).

The method is that

a) prepare a gold pulp,

b) using an absorbent prepared on the basis of liquid hydrocarbons, the density of said absorbent being lower than the density of said pulp,

c) provide contact of the pulp with the absorbent, in which free gold passes from the pulp to the absorbent,

d) free gold is recovered from the absorbent by filtering the absorbent.

A feature of the known method is that the gold-bearing pulp is fed from the bottom to the separator. In the separator, said pulp passes through a filter, which is located in the middle part of the separator, while this filter is a layer of polystyrene foam granules that partially adsorb gold. After filtering, the pulp is fed to the upper part of the separator, where the liquid layer of the absorbent, which is prepared on the basis of liquid hydrocarbons, is located, while the specified absorbent layer is held on the surface of the pulp, and the pulp and absorbent contact in the near-surface zone of the adsorption layer.

The disadvantages of this method are:

- the surface contact of the absorbent with the pulp leads to low extraction efficiency of free gold of large, medium, small, thin, dusty and dispersed classes, and the surface contact of the pulp and absorbent does not allow the gold to be firmly held in the absorbent layer, which also reduces the extraction of free gold;

- fast clogging of the filter from expanded polystyrene granules with sludge material and a decrease in the rate of filtration of the pulp, the formation of sludge plugs and the termination of the filtering process,

- low efficiency of extraction of free gold from poor placers and ores, which mainly contain thin, silty and dispersed classes.

Therefore, the known method of extracting free gold from placers and ores did not find industrial application.

SUMMARY OF THE INVENTION

The present invention is to develop a method and device for extracting free gold from placers and ores, the use of which will increase the degree of extraction of free gold of all classes, including small, thin, dusty and dispersed from natural and man-made placers and ores.

Another objective of the present invention is to develop a method and device for the extraction of free gold from placers and ores, the use of which will organize industrial extraction of free gold from refractory deposits, which mainly contain free gold of small, thin, dusty and dispersed classes.

Another objective of the present invention is to develop a method and device for extracting free gold from placers and ores, the use of which will reduce the costs associated with the extraction of free gold of small, thin, dusty and dispersed classes.

Another objective of the present invention is the extraction of free gold from gold-containing sludges, namely, waste processing of iron ore, bauxite, manganese, potassium salts, titanium-zirconium placers.

Other objectives and advantages of the present invention will be disclosed below as the present description and drawings.

METHOD FOR REMOVING FREE GOLD FROM SCALES AND ORES

OPTION №1

According to the first embodiment of the present invention, the problem is solved in that in the known method for the extraction of free gold, according to which,

a) prepare a gold pulp,

b) using an absorbent prepared on the basis of liquid hydrocarbons, the density of said absorbent being lower than the density of said pulp,

c) provide contact of the pulp with the absorbent, in which free gold passes from the pulp to the absorbent,

d) release free gold from the absorbent by filtration

absorbent, according to the claimed invention,

e) carry out volumetric contact of the pulp with the absorbent by filtering the pulp through at least one layer of absorbent material,

f) using an absorbent with an oxidizing potential (Eh) and characterized by an adhesion to free gold of at least 40 Pa.

In a particular embodiment of the method, volumetric contact of the pulp with the absorbent is carried out by filtering the pulp from top to bottom through at least one layer of absorbent material.

In a particular embodiment of the method, the absorbent has an oxidizing potential (Eh) of at least +1400 mV.

In a particular embodiment of the method, liquid hydrocarbons are used as absorbent, for example: mineral oil obtained after processing fuel oil, engine mineral oil of various grades or their mixtures with the addition of activating substances and heat treatment of the mixture.

In a particular embodiment of the method, the density of the absorbent is 0.72-0.93 g / cm ³ .

In a particular embodiment of the method, the pulp density is 1.1-1.6 g / cm ³ .

In a particular embodiment of the method, filtering the pulp through the absorbent layer is carried out under a pressure of not more than 0.1-0.5 MPa.

OPTION №2

According to the second option, the problem is solved by the fact that in the known method of extracting free gold from placers and ores, according to which,

a) prepare a gold pulp,

b) using an absorbent prepared on the basis of liquid hydrocarbons, the density of said absorbent being lower than the density of said pulp,

c) provide contact of the pulp with the absorbent, in which free gold passes from the pulp to the absorbent,

d) release free gold from the absorbent by filtration

absorbent, according to the claimed invention,

e) carry out volumetric contact of the pulp with the absorbent by filtering the pulp from top to bottom through at least one layer of absorbent material,

f) using an absorbent with an oxidizing potential (Eh) of at least +1400 mV and characterized by an adhesion to free gold of at least 40 Pa.

In a particular embodiment of the method, liquid hydrocarbons are used as absorbent, for example; mineral oil obtained after processing fuel oil, engine mineral oil of various grades or their mixtures with the addition of activating substances and heat treatment of the mixture.

In a particular embodiment of the method, the density of the absorbent is 0.72-0.93 g / cm ³ .

In a particular embodiment of the method, the pulp density is 1.1-1.6 g / cm ³ .

In a particular embodiment of the method, filtering the pulp through the absorbent layer is carried out under a pressure of not more than 0.1-0.5 MPa.

DEVICE FOR EXTRACTION OF FREE GOLD FROM SCALES AND ORES

Also according to the present invention, the problem is solved in that in the known device for extracting free gold from placers and ores, containing

a) at least one separator,

b) at least one pipe for supplying gold pulp to said separator,

c) at least one pipe for removing pulp from the separator,

d) at least one pipe for supplying absorbent material to the separator,

e) at least one pipe for removal of absorbent,

f) at least one filter press connected to said absorbent outlet pipe,

according to the claimed invention,

g) the separator contains at least one layer of absorbent prepared on the basis of liquid hydrocarbons, the density of which (0.72-0.93 g / cm ³ ) is less than the density of the pulp (1.1-1.6 g / cm ³ ) while the absorbent has an oxidizing potential (Eh) and the adhesion to free gold is not less than 40 Pa, while the said absorbent layer acts as a filter for filtering gold-bearing pulp.

In a particular embodiment of the device, the separator further comprises at least one pulp mixer with an absorbent located in the upper part of the separator.

In a particular embodiment of the device, the separator further comprises at least one means for measuring the level of pulp in the separator.

In a particular embodiment of the device, the pulp discharge pipe is located in the lower part of the separator and contains a hydraulic shutter to form the pulp level in the separator.

Gold is in the 1st group of the sixth period of the periodic table of the system of elements D.I. Mendeleev. This means the presence of 6 electronic orbitals of an atom with one electron in the outer orbit. Two outer electron layers, consisting of 1 and 18 electrons, are valence, that is, they are able to give part of their electrons under the influence of strong oxidizing agents, turning into 1 or 3 valence cations (AuCl, AuCl ₃ , Au ₂ Br ₂ ).

Gold has the maximum electronegativity for metals, that is, the maximum ionization potential necessary to detach an electron from an external orbit, as well as its maximum electron affinity. The ability of gold to retain external electrons in its sphere is estimated by the ionization potential at 9.22 eV, and the closest analogue of silver at 7.577 eV. By the magnitude of the ionization potential, gold is close to strong oxidizers of the 6th group, which have 6 electrons in their atomic structure on the outer shell - Te, Se, S, O. Even with these elements, gold does not enter into chemical compounds by the type of ionic bonds. Therefore, in ordinary natural conditions, free gold is inert.

Gold reacts well with the formation of chemical ionic bonds with most halogens - F, Cl, Br, which have a very high ionization potential (electronegativity) of 21.59 eV.

Therefore, they strongly affect the external electronic shells of gold.

, $$Au{\left(OH\right)}_2^{-}$$

, $$Au{\left(SO\right)}_2^{3-}$$

.Under natural conditions, the migration of gold, which passes into underground and river waters under the influence of halogens and organics, occurs in the form of 1 or 3 valence anions $$AuC{l}_2^{-}$$

, $$Au{\left(OH\right)}_2^{-}$$

, $$Au{\left(SO\right)}_2^{3-}$$

.

Gold atoms are united by a special metal bond, which consists in the complete generalization of valence electrons between interacting atoms and their non-attachment to a specific atom. The electrons in gold form, as it were, an electronic gas capable of moving under the influence of superimposed electric potentials.

The surface of the gold has a positive charge, in addition, the elongated forms of gold have a dipole moment. The ends of the golds have positive and negative charges, due to which they are joined on the surface of the water by an electrostatic bond in chains. The nature of the formation of the dipole moment of zolotins has not been studied. It is assumed that it is associated with an excess and deficiency of the electron cloud at different ends of elongated gold, which can be caused by a difference in the shape, area, and tip of the gold. Molecular, mainly, dispersed attractive forces of golds are sufficient for the formation of a chain agglomeration of gold on water.

Gold grains of free gold have a high positive surface charge, and also have a pronounced hydrophobicity.

A positively charged hydroxonium of water (H ₃ O ⁺ ) is electrostatically repelled from the charged surface of a free gold particle. Hydroxyl ion (OH) ^- forms weak intermolecular (dispersion) bonds with the surface of the gold. Therefore, the film of hydroxyl ion during filtration is easily removed from the surface of the gold.

The vast majority of rock minerals in placers have negatively charged surfaces, which is associated with the placement of oxygen atoms, hydroxyl groups, negatively charged unbalanced ions on their surface.

The basal (oxygen) surfaces of the rock minerals interact with the positively charged hydroxonium ion (H ₃ O ⁺ ). A strong chemical covalent bond between the negative surface of the mineral and hydrogen, hydroxonium of water leads to the formation of an adsorbed layer of strongly bound water. The molecules of this layer hold and orient dipoles of water in the immediate environment of the mineral. A double electric layer of firmly bound and film water is formed. The thickness of the layer of water held by the mineral varies between 10-100 nm. It depends on the electric potential of a solid, the concentration of electrolyte, and the pH of the aqueous medium. Ore minerals are hydrophobic and exhibit lyophilic properties (well wetted by oils). Thick hydrated rocks are not wetted by oils.

The difference in hydrophilicity and lyophilism of gold and non-metallic materials is the basis of the present invention.

A distinctive feature of free gold is increased adhesion to fat surfaces, bitumen, oil refining residues, carbon, mineral oils, wood and activated carbons.

Mineral oils belong to the group of liquid hydrocarbons, which, for example, are obtained after processing fuel oil. They are a complex mixture of hydrocarbons and non-carbon (heteroatomic) components. The composition of mineral oils includes saturated, unsaturated, aromatic hydrocarbons (paraffinic, fatty or aliphatic hydrocarbons, naphthenic hydrocarbons). Their ratio in mineral oils varies depending on the quality of the primary oil and its processing methods. In addition to hydrocarbons, mineral oils contain oxygen, sulfur and nitrogen organic compounds, in particular organic sulfides, sulfoxides, which are good extractants of dissolved forms of gold.

Hydrocarbons of mineral oils are the simplest organic compounds of carbon and hydrogen. The atoms of these elements join in the form of a covalent bond with the formation of branched chains, which is a specific feature of organic substances.

Carbon atoms will be interconnected and atoms of other elements in the form of straight, branched and ring chains. Unlike inorganic carbon compounds, the structure of carbon bonds in organic chains is very strong. This is because the carbon atom is always 4-valent, that is, it restores its external orbital by the addition of 4 electrons, or gives its 4 electrons from the external orbit to a stronger oxidizer. 4 electronic covalent bond is very strong. The covalent bond of carbon atoms with hydrogen or chlorine leads to a change in the valence of carbon by -4 and +4, respectively. In compounds with hydrogen, the electron density is shifted to carbon, where the negative charge is concentrated (-4e), and in compounds with chlorine, the carbon is positively charged (+ 4e). This leads to the formation of dipoles and dipole moments. The negative charge of hydrocarbon molecules at the end of the dipole is the main binding factor of organometallic compounds by the type of molecular (dispersion) chemical bond.

In addition, hydrocarbon oils in their structure have phenolic, creosol and pyridine polar groups. Mineral oils also include aliphatic and aromatic sulfides of the composition:

- C ₂ H ₆ S; C ₃ H ₈ S; C ₄ H ₁₀ S; C _n H _{n + 2} S — aliphatic sulfides;

- C ₄ H ₈ S; C ₅ H ₁₀ S; C _n H _2n S - cyclic sulfides.

For aliphatic hydrocarbons (methane and its homologs — CH ₄ ; C ₂ H ₆ ; C ₃ H ₈ ; C _n H _{2n + 2} ), the removal of one hydrogen atom leads to the appearance of a negatively charged monovalent hydrocarbon radical C _n H _{2n + 1} . Radicals are formed during the decay of organic molecules by heat.

; $$CC{l}_4^{(+)}$$

). Образуются диполи со смещением электронного облака в сторону элементов, замещающих водород (галогены - Br, Cl, S). На конце диполей с атомами галогенов или серы появляется отрицательный заряд, у атома углерода - положительный. Дипольные моменты - произведение величины зарядов атомов диполя и расстояние между ними определяют силу молекулярных химических (дисперсионных) связей, в частности между атомами золота, диполями золотин и диполями минерального масла. С увеличением зарядов атомов в диполе возрастает дисперсионная сила взаимодействия веществ.The departed hydrogen atoms are replaced by halogen atoms, oxygen, sulfur, while the valency of carbon changes from negative to positive ( $$C{H}_{\mathrm{four}}^{(-)}$$

; $$CC{l}_{\mathrm{four}}^{(+)}$$

) Dipoles are formed with the displacement of the electron cloud in the direction of the elements replacing hydrogen (halogens - Br, Cl, S). A negative charge appears at the end of dipoles with halogen or sulfur atoms, and a positive charge at the carbon atom. Dipole moments - the product of the magnitude of the charges of the atoms of the dipole and the distance between them determine the strength of molecular chemical (dispersion) bonds, in particular between the gold atoms, dipoles of zolotins and dipoles of mineral oil. With an increase in atomic charges in a dipole, the dispersion force of the interaction of substances increases.

The atoms with the maximum charge and minimum radius are distinguished by the greatest activity and ability to replace hydrogen reactions in liquid hydrocarbons. According to these criteria, a number of substitution activities are presented:

Br → CI → S → F → O → P → N

Sorption of free gold is carried out due to the chemical intermolecular bond of Van der Waals. It is caused by the interaction of adsorbent dipoles with atoms and molecules of free gold and consists in the displacement of the electron shells of gold atoms, the formation and amplification of their dipole moments.

The intensity of the interaction of wetting liquids and gold depends on the polarity of the absorbent - the number of dipoles and their charge. With an increase in polar groups, the molecular interaction and the wettability of gold with an absorbent increase.

In the process of bulk contact of the pulp with the absorbent, which is prepared on the basis of liquid hydrocarbons and has a high oxidation potential (Eh) of adhesion to free gold of at least 40 Pa, all the golds that are in the pulp selectively accumulate in the absorbent, and the rock minerals are removed from the separator. In the process of volumetric contact, the golds are actively wetted by an absorbent that displaces water, resulting in a decrease in the surface energy of the gold. Since the adhesion to free gold is at least 40 Pa, this leads to the fact that the gold of all classes of fineness, including large and dispersed gold, is retained in the absorbent layer. As a result of increased density (14-19 g / cm ³ ), especially high-quality free gold, the gold moves in the absorbent layer and accumulates in the lower part of the absorbent layer - in the contact zone of the absorbent and pulp.

During volumetric contact of the pulp with an absorbent that has an oxidizing potential (Eh) of more than +1400 mV and adhesion of at least 40 Pa, free gold of all particle sizes is extracted.

During the experiments, it was found that with the adhesion of the absorbent to free gold of at least 40 Pa and a gold density of 16-19 g / cm ^3, free gold of average fineness ~ 16 g / cm ³ can be held by absorption bonds at a size of 0.6-1, 5 mm or more, that is, loose gold of a large class. High-quality free gold (18-19 g / cm ³ ) with plate-shaped sizes of gold more than 0.15-0.2 mm is also retained by the absorbent in the separator.

The metal content of gold per unit area of the absorbent layer is 90-110 mg / cm ² when the adsorbent adheres to free gold of at least 40 Pa and the oxidation potential (Eh) of at least +1400 mV.

BLUEPRINTS

When considering embodiments of the present invention, narrow terminology is used. However, the present invention is not limited to the accepted terms and it should be borne in mind that each such term covers all equivalent elements that work in a similar way and are used to solve the same problems.

So, the present invention is illustrated in the drawing, which shows:

device for extracting free gold from placers and ores.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. shows a device for extracting free gold from placers and ores, which contains a separator 1, a supply pipe of gold-bearing pulp 2 located in the upper part of the separator 1, a pipe outlet of the pulp 3 located in the lower part of the separator 1, a pipe for supplying absorbent 4 to the separator 1, pipe removal of the absorbent 5 from the separator 1, the filter press 6 connected to the pipe of the removal of absorbent 5. A container 7 for collecting absorbent material connected to the filter press 6 and the pipe of the supply of absorbent 4.

The separator 1 contains a layer of absorbent 8, which floats on the surface of the pulp 9.

Also, the separator 1 contains a mixer 10 of the pulp with absorbent material, which is located in the upper part of the separator 1 in the adjoining zone of the nozzle for supplying the gold-bearing pulp 2 to the separator 1.

Also to the separator 1 is adjacent to the pipe for supplying air 11, which is adjacent to the upper part of the separator 1.

The supply pipe of the gold-bearing pulp 2, the discharge pipe of the pulp 3, the intake pipe of the absorbent 4, the intake pipe of the absorbent 5 and the air supply pipe 11 contain regulators 12 ₁ , 12 ₂ , 12 ₃ , 12 ₄ and 12 ₅ .

Also, the supply pipe of the gold-bearing pulp 2 contains a pump 13 for feeding the pulp from the source of pulp 14 to the separator 1.

The filter press 6 contains a removable cartridge, which is a steel mesh cylinder in which the filter is placed.

The pipe for supplying absorbent 4 contains a pump 16 for supplying absorbent from the tank 7 to the separator 1.

The pipe outlet pulp 3 forms a hydraulic shutter 17.

As it was mentioned above, position 14 indicates the source of pulp production, which can be: pulp formers of dredging pumps, pulp pumping stations of processing plants, slurry pipelines, dredges, industrial devices at existing and worked out areas of placers, tailings for processing plants, tailings, sedimentation tanks, etc.

The separator 1 also contains a pulp level indicator, a pressure gauge and an emergency pressure relief valve, which are not shown in the figure.

Also, the pipe outlet 3 may contain at least one vibrator (not shown in FIG.) To remove plugs in the pipe outlet 3.

EXAMPLE 1

A method of extracting free gold from placers and ores, according to which a gold-bearing pulp is prepared, which leaves the source of pulp 14 and feeds it into the separator 1 through the supply pipe of the gold-bearing pulp 2. In the separator 1, the pulp is sprayed through a mixer 10 and passes through an absorbent layer 8, which acts as a liquid filter to filter gold pulp. When this layer of absorbent 8 is located on the surface of the pulp 9 in the separator 1.

As a result of the volumetric contact of the pulp with the absorbent layer 8, the selective transfer of gold from the pulp to the absorbent is carried out, as well as the separation of the hydrophilic and hydrophobic parts of the gold-bearing pulp.

Due to differences in pulp densities and absorbent pulp, the pulp settles at the bottom of the separator 1 and is withdrawn from it through the pipe outlet 3.

The amount of pulp that must be passed through the absorbent layer 8 in one filter cycle to achieve maximum metal consumption of the absorbent layer 8 is determined experimentally.

After passing the gold-bearing pulp through the absorbent layer 8, the pulp was stopped in the separator 1, after which the absorbent was removed from the separator 1 by means of the absorber discharge pipe 5 to the filter press 6. In the filter press 6, the absorbent was filtered, resulting in gold or grain (combination Zolotin) deposited on the surface of the filter cloth removable cartridge 15.

After filtration, the absorbent was removed from the filter press 6 into a container 7 from which through the nozzle supply line of the absorbent 4 by means of a pump 16, the absorbent was supplied from the container 7 to the separator 1 and thereby the absorbent layer 8 was formed in the separator 1. After the absorption layer 8 was formed in the separator 1 gold pulp was fed into the separator 1 and pulp was passed through the absorbent layer 8.

After filtering the absorbent and removing it from the filter press 6, a removable cartridge 15 was removed, from which a cloth filter was removed with the extracted golds, a macro- and microscopic study of gold was performed, and then the filter was burned at a temperature of ~ 700 ° C to obtain a solid residue with gold.

In the case of the formation of traffic jams in the pipe outlet of the pulp 3, air was supplied to the separator 1 through the pipe of the air supply 11.

EXAMPLE No. 2

Experience with "single" samples.

In samples weighing 1 kg. fine-grained alluvial quartz sand with a grain size of 0.1-0.2 mm, 100 585 gold samples of 0.1-0.15 mm size were introduced.

After that, the samples were thoroughly mixed and placed in a pulp sampler (position 14, the source of pulp production), in which a gold-bearing pulp was formed. The obtained gold-bearing pulp was fed into the separator 1, according to example No. 1.

The test results for 10 samples are presented in table 2, while the pulp density was the same and equal to 1.1 g / cm ³ and the oxidative potential of the absorbent (Eh) changed.

From table 2 it is seen that when using an absorbent with adhesion to free gold of at least 40 Pa, the amount of free gold increases with increasing oxidation potential (Eh), and the sensitivity of detection of free gold increases to 30-40 mg / t, which indicates that the invention may be industrially applicable for the detection and extraction of free gold from refractory and poor placers and ores.

EXAMPLE No. 3

Experience with "single" samples.

In samples weighing 1 kg. fine-grained alluvial quartz sand with a grain size of 0.1-0.2 mm, 100 585 gold samples of 0.1-0.15 mm size were introduced.

After that, the samples were thoroughly mixed and placed in a pulp sampler (position 14, the source of pulp production), in which a gold-bearing pulp was formed. The obtained gold-bearing pulp was fed into the separator 1, in accordance with example No. 1.

The test results are presented in table 3.

From table 3 it is seen that with an increase in the density of gold-bearing pulp (growth of solid in the ratio "Solid: Liquid"), the degree of extraction of free gold decreases under similar conditions in Example No. 2-3, and the sensitivity of the analysis decreases - 48-52 mg / t. However, the selectivity of free gold recovery is 1 sign of gold per 70-90 million grains per 1 kg of fine-grained alluvial quartz sand is preserved, which indicates that the invention can be used to extract free gold at different pulp densities.

EXAMPLE No. 4

When conducting the experiments described in the above examples No. 2 and 3, the absorbent costs were also measured in the process of extracting free gold. The results on the consumption of absorbent during the extraction of free gold are presented in table No. 4.

EXAMPLE No. 5

Field experiments.

Tests of the claimed invention were carried out in the field. The results of the extraction of free gold from the waste from the concentration plants are presented in table No. 5. The weight of the sign of free gold in the class is determined by calculating the average volume of flat golds - the predominant flake gold and a gold density of 16.0 g / cm ³ .

From the above table it follows that the use of the claimed invention allows to extract free gold from placers and ores of large, medium, small, thin, dusty and dispersed classes from natural and man-made placers and ores, including so-called floating gold of small, thin and dusty classes is extracted.

Table 5 shows that all classes of free gold are extracted, and the amount of free gold obtained indicates the industrial concentration in the spent sludge.

From the above tables 2-5 it follows that the use of the claimed invention allows to extract free gold of all classes of fineness from natural and man-made placers and ore processing wastes (tailings).

With an oxidizing potential (Eh) of at least + 1400 mV, high-grade gold of large and medium classes, as well as small and thin “floating” fractions, are effectively extracted.

Moreover, the productivity of industrial devices for the extraction of free gold from placers and ores can reach 800-1000 m ³ / day or more. Gold metal consumption per 1 filter cycle, calculated on the absorbent layer area - 90-110 mg / cm ² , free gold detection sensitivity -30-50 mg / t, extraction selectivity - 1 gold sign per 70-100 million grains of fine-grained alluvial quartz sand .

The use of the present invention does not harm the environment, since basically the extraction of free gold is planned from waste from existing plants.

The technical result of the claimed invention is:

- increase the efficiency of extraction of free gold of small, thin, silty and dispersed classes, the so-called "floating" gold;

industrial organization for the extraction of free gold from refractory deposits, which mainly contain free gold of small, thin, dusty and dispersed classes;

- increase the efficiency of extraction of free gold from poor placers and ores, which mainly contain thin, dusty and dispersed classes of gold;

- reduction of costs associated with the extraction of free gold of small, thin, dusty and dispersed classes from natural and man-made placers and ores;

- reduction of costs associated with the extraction of free gold of small, thin, dusty and dispersed classes from natural and man-made placers and ores;

- organization of the repeated extraction of free gold from processed ores and placers, tailings, sumps, which contain free gold of small, thin and dispersed classes;

- organization of the extraction of free gold from gold-containing sludges, namely, waste from the processing of iron ore, bauxite, manganese, potassium salts and titanium-zirconium placers.

It is clear that the above are only some optimal options for putting into practice the present invention. The present invention is not limited to the options set forth above.

For example, it is obvious that the present invention can be used to extract other noble metals (Ag, Pt, Pd), as well as metals that have a similar structure of two external electron shells, such as copper, nickel, cadmium, zinc, bismuth. Moreover, the mentioned metals must be in free form.

So in accordance with the present invention for the extraction of precious metals:

a) prepare the pulp, which contains noble metals in free form,

b) use an absorbent made on the basis of modified liquid hydrocarbons, the density of which is lower than the density of the mentioned pulp,

c) provide bulk contact of the pulp with said absorbent by filtering the pulp through at least one absorbent layer, using an absorbent that has an oxidation potential (Eh) of at least +1400 mV and is characterized by an adhesion value of noble metals of at least than 40 Pa

d) in this case, as a result of said bulk contact, the noble metals selectively pass from the pulp to the absorbent,

e) after which noble metals are separated from the absorbent by filtering the absorbent in a filter press.

Moreover, this method of extracting precious metals that are in free form from placers and ores can be implemented on the above-described device for the extraction of free gold from placers and ores, which is claimed.

From the foregoing, it is obvious that the term free gold should also mean noble metals (Ag, Pt, Pd), which are in free form, or metals that have a similar structure of two external electron shells, namely, copper, nickel, cadmium, zinc, bismuth. Moreover, the mentioned metals must be in free form in placers and ores.

Claims (16)

1. The method of extracting free gold from placers and ores, including
a) preparation from placers and ores of gold pulp,
b) the use of an absorbent prepared on the basis of liquid hydrocarbons, wherein the density of said absorbent is lower than the density of said pulp,
c) contacting the pulp with the absorbent, in which free gold passes from the pulp to the absorbent,
d) the allocation of free gold from the absorbent by filtering the absorbent, characterized in that
e) carry out volumetric contact of the pulp with the absorbent by filtering the pulp through at least one layer of absorbent material,
f) using an absorbent with an oxidizing potential (Eh) and characterized by an adhesion to free gold of at least 40 Pa. 2. The method according to claim 1, characterized in that the volumetric contact of the pulp with the absorbent is carried out by filtering the pulp from top to bottom through at least one layer of absorbent material. 3. The method according to claim 1 or 2, characterized in that the absorbent has an oxidizing potential (Eh) of at least +1400 mV. 4. The method according to claim 1 or 2, characterized in that liquid hydrocarbons are used as absorbent, for example, mineral oil obtained after processing fuel oil, engine mineral oil of various grades or mixtures thereof with the addition of activating substances and heat treatment of the mixture. 5. The method according to claim 1 or 2, characterized in that the density of the absorbent is 0.72-0.93 g / cm ³ . 6. The method according to claim 1 or 2, characterized in that the pulp density is 1.1-1.6 g / cm ³ . 7. The method according to claim 1 or 2, characterized in that the filtering of the pulp through the absorbent layer is carried out under a pressure of not more than 0.1-0.5 MPa. 8. A method of extracting free gold from placers and ores, including
a) preparation from placers and ores of gold pulp,
b) the use of an absorbent prepared on the basis of liquid hydrocarbons, wherein the density of said absorbent is lower than the density of said pulp,
c) contacting the pulp with the absorbent, in which free gold passes from the pulp to the absorbent,
d) the allocation of free gold from the absorbent by filtering the absorbent, characterized in that
e) carry out volumetric contact of the pulp with the absorbent by filtering the pulp from top to bottom through at least one layer of absorbent material,
f) using an absorbent with an oxidizing potential (Eh) of at least +1400 mV and characterized by an adhesion to free gold of at least 40 Pa. 9. The method according to claim 8, characterized in that liquid hydrocarbons are used as absorbent, for example, mineral oil obtained after processing fuel oil, engine mineral oil of various grades or mixtures thereof with the addition of activating substances and heat treatment of the mixture. 10. The method according to claim 8 or 9, characterized in that the density of the absorbent is 0.72-0.93 g / cm ³ . 11. The method according to claim 8 or 9, characterized in that the pulp density is 1.1-1.6 g / cm ³ . 12. The method according to claim 8 or 9, characterized in that the filtering of the pulp through the absorbent layer is carried out under a pressure of not more than 0.1-0.5 MPa. 13. A device for extracting free gold from placers and ores, containing:
a) at least one separator,
b) at least one pipe for supplying gold pulp from placers and ores to said separator,
c) at least one pipe for removing pulp from the separator,
d) at least one pipe for supplying absorbent material to the separator,
e) at least one pipe for removal of absorbent,
f) at least one filter press connected to said absorbent outlet pipe, characterized in that
g) the separator contains at least one layer of absorbent prepared on the basis of liquid hydrocarbons, the density of which is equal to 0.72-0.93 g / cm ³ less than the pulp density equal to 1.1-1.6 g / cm ³ while the absorbent has an oxidizing potential (Eh) and adhesion to free gold of at least 40 Pa, and the said absorbent layer serves as a filter for filtering gold-bearing pulp. 14. The device according to item 13, wherein the separator further comprises at least one pulp mixer with absorbent located in the upper part of the separator. 15. The device according to item 13 or 14, characterized in that the separator contains at least one means for measuring the level of pulp in it. 16. The device according to item 13 or 14, characterized in that the pulp discharge pipe is located in the lower part of the separator and contains a hydraulic shutter to form the pulp level in the separator.