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The Common Barite Flotation Processing and Flotation Reagents

For the complex disseminated type of barite ore, the barite is often associated with fluorite, calcite, and quartz, which is difficult to be separated by the gravity separation method due to its low grade, fine disseminated grain size, and complex composition. The froth flotation method is the main barite processing method.

According to the type of salt-associated minerals, the barite ore can be divided into two categories: barite-quartz-calcite type ore and barite-fluorite type ore. Due to the similar surface chemical properties and similar flotation behavior between barite ore and associated salt minerals, the flotation process and the flotation reagents used in the different barite ores are different. Below, let’s take a look at the flotation process and reagents applied in the above two kinds of barite ore.

01 Flotation used in the barite-quartz-calcite type ore

Direct flotation method

The flotations used in the barite-quartz-calcite type ore mainly include the following:

First, add the inhibitor to inhibit the gangue minerals (such as quartz, calcite). Then, add the anion collector under the weak alkaline condition. And the barite concentrate can be obtained by roughing and 3-5 times of concentrating.

In this process, the anionic collectors can adopt fatty acids, alkyl sulfates, petroleum sulfonates, and phosphonic acid collectors, among which the fatty acids are widely used as the barite flotation collectors, such as oleic acid, sodium oleate, naphthenic acid, oxidized paraffin soap, etc.

Flotation-gravity separation combined process

First, add the sodium silicate and collector to remove the quartz by flotation processing method. Then, adopt the gravity separation method to obtain the barite concentrate according to the density difference between gangue minerals and barite ore.

Since the quartz, calcite, and barite are belong to the calcium ion compounds with similar lattice and floatability, the single flotation reagents cannot reach the desired goal. Therefore, the combined flotation reagents are often used to achieve a better barite flotation effect.

02 Flotation used in the barite-fluorite type ore

The flotation used in the barite-fluorite type ore means to inhibit the gangue minerals (such as quartz), and obtain the barite-fluorite mixed concentrate through the bulk flotation, then separate the barite and fluorite by the flotation method. According to the flotation sequence of barite and fluorite, we can adopt the following two schemes: one is to inhibit the barite then float the fluorite; another is to inhibit the fluorite then float the barite.

Inhibit the barite then float the fluorite

This barite flotation processing means to obtain the mixed concentrate of barite-fluorite firstly by flotation, and then add the inhibitor to suppress barite and float the fluorite. This barite flotation processing can simultaneously recover the barite concentrate and fluorite concentrate with the high grade.

In the barite flotation processing, the barite inhibitors mainly include tannin extract, starch, dextrin, sodium lignin sulfonate and other polymerized carbohydrates, sodium silicate, sodium carbonate, sulfate, sodium hexametaphosphate, ferric (Fe3+) and aluminum (Al3 +) and other inorganic salts, as well as the combined inhibitors.

Inhibit the fluorite then float the barite

Add the inhibitors to suppress the fluorite in the mixed barite-fluorite concentrate, and obtain the barite concentrate through flotation processing. Then, add the fatty acid collectors and sodium silicate to the tailings, obtain the fluorite concentrate by several times (7-9 times) of concentrating. This barite flotation processing is featured with the simple flow and easy to operate, which can obtain the qualified barite concentrate, but the grade of fluorite concentrate is often not high, so it is suitable for the ore that only requires to recover the barite.

In this barite flotation processing, the common fluorite inhibitors include sodium silicate, sodium fluosilicate, citric acid, lignin, sodium hexametaphosphate, and starch.

At present, the flotation method has been widely used in the separation of barite ores with the low grade of barite ores and complicated ore properties. It is suggested to carry on the mineral processing test, comprehensively analyze the ore properties, make a scientific flotation process and follow a reasonable flotation reagent system according to the actual conditions of the barite processing plant and the investment budget, so as to obtain the ideal economic benefits and beneficiation indexes.

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Guide of Alluvial Gold Mining Process and Equipment

There are many kinds of alluvial gold deposits. The gold is in a free state in the alluvial gold deposit and has the obvious specific gravity difference with sand, so the gravity separation process is an ideal and efficient method to extract gold from placer.

The alluvial gold mining process generally adopts the gravity separation process to extract the gold from the raw ore and those associated heavy minerals as much as possible (the lower limit of particle size limit is usually 0.01 mm), and then adopts the gravity separation, flotation, magnetic separation and electrostatic separation method to separate the gold and various heavy minerals, so as to achieve the comprehensive recovery.

In the production process, the common alluvial gold mining process mainly includes washing, screening, gravity separation and concentration.

01. Washing

The ore washing is an important procedure before the separation of alluvial gold, whose main purpose is to separate the gravel, sand and granular soil, wash the fine mud and the gold ore mixed in it. In general, the alluvial gold ore usually contains more weathered clay, the gold ore is wrapped in it, and form the cemented block or mud body together. If they are not broken up in advance, the cemented block or mud body will be discharged along with waste rock in the screening process, thus reducing the recovery rate of alluvial gold and causing the loss of gold.

In the ore washing operation, wash the ores with the water and then dissociate the ore sand wrapped in the cemented block or mud body through the plane vibrating screen, cylinder washing machine, cylinder screen, so as to separate the gravel, sand and clay, wash the clay and gold grains adhered to the gravel. This operation can improve the separation ability of alluvial gold ore and increase the recovery rate of alluvial gold ore.

02. Screening

In general, the main purpose of the screening is to screen the alluvial gold ore after washing, remove the large pieces of gravel without gold, so as to improve the efficiency of gold extraction. In general, the screening operation can remove 20-40% of waste rock (gravel, pebbles).

The screening of alluvial gold mining usually adopts the water screen to disintegrate the ore mud, which can improve the screening efficiency of alluvial gold mining. Usually, the size of the screen mesh used in the alluvial gold screening needs to be determined according to the composition parameters of the gold particle size in the original ore sand. At the present, the common screen mesh is generally 10-20mm.When adopting the fixed chute for the roughing, the size of screen mesh can be larger, but cannot exceed 60mm. The fixed concentrators often adopt the vibrating screen or grid screen as the screening equipment, and the gold dredger often adopts the cylinder screen.

03. Gravity Separation

The gravity separation process is mainly used in the alluvial gold mining. First, the alluvial gold ore has the large proportion and coarse particle size (generally 0.074~2mm). Second, the gravity separation has the advantages of low cost and simple process. The gravity separation is the key in the separation stage of alluvial gold mining. Adopting the jig, shaking table and spiral chute to discharge the most of waste rock, so as to obtain the coarse gold concentrate.

Jig

On the premise of specific gravity difference ≥1.25 and ore monomer disintegration, the lower limit particle size of jigging in the alluvial gold mining can reach 0.04mm. the jigging has the advantages of simple operation and large processing capacity, which is widely applied in the roughing.

Shaking table

The shaking table is suitable for processing the minerals with fine particle size, which is featured with is stable and reliable operation, clear ore belt distribution, higher rich ore ratio than other gold extraction methods, easy-to-manage, one-time ore separation. According to the different particle size of the ore, the shaking table can be divided into coarse sand shaking bed, fine sand shaking bed and mud shaking bed:

◆ Coarse sand shaking bed is suitable for processing the minerals size between 0.5mm and 2.0mm;

◆ Fine sand shaking bed is suitable for processing the minerals size between 0.074mm and 0.5mm;

◆ Mud shaking bed is suitable for processing the minerals size between 0.037mm and 0.074mm.

Spiral Chute

According to the particle size, the chute can be divided into coarse-grained chute and fine-grained chute. What’s more, the fine grain chute can be divided into ore sand chute and slime chute.

◆ Coarse-grained chute is mainly used for the separation of alluvial gold mining, whose upper limit of feeding particle size is up to 100-200mm and the lower limit of particle size is about 0.074mm.

◆ Fine-grained chute is often used for the roughing of coastal alluvial gold mining (the gold ore particle size is -2mm);

◆ The ore sand chute is suitable for the size between 2mm and 0.074mm

◆ The slime chute is used to for the size of -0.074mm.

04. Concentration

According to the different types of alluvial gold ore, the concentration can adopt the gravity separation, magnetic separation, flotation, electric separation or combined separation methods to separate the gold from the various heavy minerals, so as to further improve the grade of gold. It is necessary to pay the special attention to the selection of concentration processing method and equipment for avoiding the loss of gold in the concentration process, and fully improving the recovery efficiency of gold and other heavy sand minerals, so as to achieve the purpose of comprehensive recovery.

05. Dewatering

In general, the dewatering operation is determined based on the process used in the concentration stage. The gravity separation, magnetic separation and flotation process can be carried out under the wet conditions, while the electric separation process requires the dry conditions. In general, the dewatering stage of alluvial gold mining adopts the concentration + filtration process.

In the actual production, the selection of alluvial gold mining process and equipment is related to the ore properties, plant condition, investment budget and other factors. The same alluvial gold mining process and equipment cannot be fully applicable to all the alluvial gold concentrator. Therefore, it is recommended to choose equipment manufacturers with mineral processing qualifications to customize the scientific and reasonable alluvial gold mining.

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Here Are All flotation Separation Processes for Different Types of Fluorite Ore

Fluorite is an important non-metallic mineral resource and the main source of fluorine in the industry. It is widely used in metallurgy, aluminum smelting, glass, ceramics, cement, chemical industry and other fields.

There are three kinds of processing processes of fluorite: hand separation, gravity separation and flotation separation. Among them, hand separation and gravity separation are mostly used as auxiliary separation and pre-separation, while flotation separation is the main method. According to different associated minerals, fluorite ores can be divided into quartz-type fluorite ore, calcite-type fluorite ore, barite-type fluorite ore and polymetallic symbiosis type fluorite ore, etc. The flotation processes of each mineral are different with different properties.

01 Flotation separation of quartz-type fluorite ore

Quartz-type fluorite ore is mainly composed of fluorite (content 80%-90%) and quartz, accompanied by a small amount of calcite, barite, pyrite and kaolinite and other minerals.

For the flotation of this type of fluorite ore, fatty acids are often used as collectors, sodium carbonate is used as a slurry pH adjuster (pH value is 8-9), and water glass is used as an inhibitor. The high-quality fluorite concentrate can be obtained after several selections.

It is worth noting that the quartz-type fluorite ore is divided into coarse-grained fluorite ore and fine-grained fluorite ore according to the embedding characteristics of useful minerals. In the above flotation method, fine-grained embedded fluorspar ore has increased flotation difficulty due to its finer particle size, so it is necessary to strengthen the grinding operation to improve the monomeric dissociation of the target minerals.

02 Flotation separation of calcite-type fluorite ore

Calcite-type fluorite ore is dominated by fluorite, and co-associated ores include calcite (30% or more) and a small amount of quartz, sometimes in the form of quartz-calcite-fluorite ore.

Since fluorite and calcite are both calcium-containing salt minerals with similar solubility, both have strong adsorption operation when fatty acids are used as the collector. Therefore, it usually adopts inhibitors of calcium-containing minerals (such as water glass, sodium metaphosphate, lignin sulfonate, dextrin, tannic acid, oxalic acid), oleic acid as the collector, and sodium carbonate as the pH regulator (pH value of 8~9.5) to separate by bulk flotation first, and then conduct the fluorite and calcite flotation separation. In order to improve the inhibition effect, the reagents are mostly added to the flotation slurry in the combined form.

03 Flotation separation of barite-type fluorite ore

Barite-type fluorite ore is dominated by barite (content 10%-40%) and fluorite ore, with a small amount of associated pyrite, galena, sphalerite, etc. Some deposits contain a large amount of quartz, which exists in the form of barite-fluorite-quartz ore.

The flotation of this type of ore generally uses oleic acid as the collector, and water glass as the inhibitor. It processes the bulk concentrate of barite and fluorite first, followed by the separation of fluorite and barite.

There are two methods to separate fluorite and barite. One is to inhibit barite and separate fluorite by flotation, the other is to inhibit fluorite and separate barite by flotation.

(1) Inhibit barite and separate fluorite by flotation

After obtaining the bulk concentrate of barite and fluorite, aluminum sulfate, water glass and tannin extract are used as a combined inhibitor of barite, and the fluorite and barite are separated by one roughing and several flotation processes. This method obtains a higher grade of barite concentrate, but a relatively low grade of fluorite.

(2) Inhibit fluorite and separate barite by flotation

After obtaining the bulk concentrate of barite and fluorite, it uses barium chloride to activate barite, sodium hydroxide and sodium silicate to inhibit fluorite to separate barite preferentially. Then it uses oleic acid as the collector, sodium silicate and aluminum sulfate as inhibitors to separate fluorite from tailings. This process obtains a high grade of fluorite ore concentrate, but the grade of barite is relatively low.

04 Flotation separation of polymetallic symbiosis type fluorite ore

Polymetallic symbiosis type fluorite ore are mainly quartz and fluorite, and accompanied by more heavy metal minerals, such as galena, sphalerite, chalcopyrite, pyrite and scheelite, etc.

For this type of fluorite ore, the priority flotation separation is generally used to separate useful minerals in sequence. The metal sulfide minerals are preferentially separated with sulfide mineral collectors (xanthate, aerofloat, etc.), and then it uses fatty acid as the collector (oleic acid, oxidized paraffin soap, etc.) to separate fluorite ore from metal sulfide tailings.

The above are the flotation processes for different types of fluorite ore. For different properties of fluorite ore, different processes have a greater impact on the concentrate index. As for which flotation process to choose, it is necessary to determine the associated minerals in the fluorite ore through processing tests to choose a reasonable process.

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