The uniform ore slurry is slowly fed to the spiral groove surface through the ore feeding trough installed at the head end of the spiral trough for sorting. The end of the spiral groove is equipped with a valve block-type product intercepting groove, and the sorted products are divided into three types according to the grade along the radial direction. The position of the regulating valve block is used to change the intercepting width of each product, and the product gathering bucket collects and derives the intercepted multi-head ore streams. The cross section and the slope change of the curve are especially suitable for the selection of fine particle materials.
Spiral chute is suitable for treatment of the 0.6-0.03mm lode and placer, but high mud content is bad for separation. At present, the spiral chute has been widely used in the treatment of iron ore, tungsten, tin ore, niobium tantalum ore, coastal and riverside placer and gold ore.
In all rare metals, the importance and scarcity of chrome ore and scarce are most obvious, which is at the top of "strategic metals". The chrome ore is mainly used in the production of stainless steel and various kinds of alloy steel in the form of ferroalloy (such as ferrochrome), which has the advantages of strong hardness, wear-resisting, heat-resisting and corrosion resistance.
At present, the common chrome extraction processes mainly include gravity separation, magnetic separation, electric separation, flotation, gravity-magnetic separation process. Below, let's take you to learn about each chromite ore processing process.
From the point of production practice, the gravity separation is still the main chrome extraction method in the world method now, which uses the loose stratification in the water medium. At present, the gravity separator used in the chromite ore processing includes the shaker table, jig, spiral chute and centrifugal separator.
It is worth noting that stage grinding and gravity separator, or the combination of various gravity separators can be used according to the chrome ore properties, thus further improving the grade and recovery of chrome concentrate.
Because the chromite has a weak magnetism, we can use the strong magnetic separator for chrome extraction. There are mainly the following two cases: one is in the weak magnetic field, remove the ore in the strong magnetic separation of minerals (main magnetite), improve the ratio of ferrochrome. Another is to separate the gangue minerals and recover chrome ore (weakly magnetic mineral) under the strong magnetic field. If necessary, the weak magnetic - strong magnetic separation process can also be used to effectively separate the ore and achieve the chrome extraction.
The electric concentration process is mainly used to separate chromium ore from silicate gangue by using the difference of electrical properties of minerals, such as conductivity, dielectric constant, etc. For the chrome ore, a few chrome can be used directly by the electrical concentration, most of them only use the electrical concentration process in the concentration process. The concentration process has a special effect on removing silicate minerals (such as quartz, etc.) from chrome. Therefore, after the separation of chrome, another stage of the electric concentration process can be added for cleaning, which not only further improves the grade of chrome concentrate, but also greatly reduces the content of silicon dioxide.
At present, we can use the flotation process to recover the chromite with fine grain size (-100um) after the gravity separation. The results show that Mg2+ and Ca2+ can inhibit the chromium ore, and the inhibition of Mg2+ is influenced by the type of anions in the slurry. Therefore, after knowing the cationic behavior in the pulp, we can choose the appropriate pulp PH value, reagents concentration, add the order of inhibitors and activators, achieve the separation of chromite and pyrite.
Sometimes, the single gravity separation method cannot recover the chrome concentrate effectively. At this time, the concentrate obtained by the gravity separation can be separated by weak magnetic separation or strong magnetic separation, further improving the grade of chrome concentrate and chromic oxide-ferrous oxide ratio.
For example, the 100-10mm grade of raw ore adopts two-stage dense media separation. The medium ore of the dense media separator is crushed to 10-0mm and then merged with the 10-0mm grade of raw ore for separation. The grades of 10-3mm and 3-0mm are sent to the jigging process. After the middling of the jigging process is ground to 0.5-0mm, the spiral concentrator is used for separation, and the shaker table is used for the separation of mineral mud (0.5-0mm). Then, the high-field magnetic separator is used to recover 0.25mm slime separated from the tailings of the shaker table and spiral separator, ensuring the content of chromium oxide in the concentrate and reduce the loss of valuable components in the tailings.
Here are the common five chrome extraction processes. For the rich ore with high chromium oxide content, single gravity separation or magnetic separation process can be adopted. For the chrome with low chromium oxide content, the combined process of gravity separation and magnetic separation usually gets a better index than the single process. Of course, the specific chrome extraction process should be determined comprehensively according to the nature of the chrome ore, the actual situation of the chromite ore processing plant, the investment budget, so as to ensure the ideal beneficiation benefits and economic benefits.
This small scale rock gold processing plant is suitable for 1-2 tph capacity.It will include a jaw crusher, a hammer mill, a ball mill and 1-2 sets of shaking tables. Except these machines, you can also add a 8-10 meters belt conveyor and make a hopper with grizzly bars. It will help you to feed the ores by the load vehicle. Contact Us to get more details of this processing plant.
1. The 1st step Crushing. The Raw rock minerals will be fed into the crushers to get the discharge size less then 25mm. Usually it will need 2 crushers, the primary crusher is for cutting down the big size of rocks, and the second crushers is for getting the size of -25mm.
2. The 2nd step Grinding. The grinding machine will be ball mill or wet pan mill. If you need to grind the minerals without waters, then you should choose ball mill. The ball mill has a grinding rotary drum, there are liners inside of the drum. Usually the liners are manganese steel liners, some times, the customers ask the liners can be corrosion resistant, so we will make ceramic liners and rubber liners. The discharge size from the ball mill will be around 200 mesh. It will make a good performance for the mineral particle separators by gravity separators or flotation machines.
3. The 3rd step Separating. The discharge from the grinding machines will be in the size of 0-2mm. Most gravity separators can do a good work for separating the concentrate from the ores. It includes the shaking tables, centrifugal concentrators, jigger machines and spiral chutes. Sometime, we do also choose the flotation machines to get the concentrate mud. It depends on the ores situations.
Due to the size,shape and specific gravity of alluvial gold, the most effecient method is using washing plant. It always includes a trommel screen, vibrating sluice boxes, a centrifugal concentrator and shaking tabls. If the alluvial gold with very sticky clay, then the trommel screen should be changed into a rotary scrubber with a trommel screen.
We have more than 25 years experience, and the machines are sold to all over the world. Our engineers can go to your local mining site for leading the processing plant installation and train your staffs.
Spiral Chute is the best equipment for mining and mineral processing, which combines the characteristics of the spiral concentrator, shaking table and Centrifugal concentrator. It is made of the fiberglass lined with wear-resistant polyurethane and corundum cover, light moisture proof, anti-rust. It is mainly used for separation and recovery of a wide range of minerals: zircon, ilmenite, rutile, iron ore, chromite, manganese, tin, tantalum and tungsten ore, silica sands, gold, copper and base metals and etc., as well as other non-ferrous metals, rare metals and non-metallic minerals.
The Spiral separator/ spiral chute is the earliest mining machine. It has been used in to classify the granularity 0.3-0.02 millimeters fine grain like iron, tin, tungsten, tantalum-niobium, gold ore, coal mine, monazite, rutile, zircon, and other metals. The non-metallic minerals which have a big enough specific gravity difference.
Raise the spiral chute and fix it in the proper position, sand pump transport the ore to the feed inlet, adding water to adjust the concentration of the slurry. The slurry naturally swirls from high to low, and generates an inertial centrifugal force in the rotating bevel flow rate. The mineral is separated from the sand by the gravity and centrifugal force of the swirl by the difference in specific gravity, grain size and shape of the ore. The concentrate flows into the concentrate bucket and is connected by the pipeline. The tail sand flows into the tailing sand bucket and is connected to the sand pool by the pipeline, and then drained by the sand pump to complete the whole process of the beneficiation.