Heavy media are divided into two major categories: heavy liquids and heavy suspensions. The heavy liquid is an aqueous solution of some dense organic liquid or inorganic salt, which can be formulated into different densities by using an organic solvent or water. Heavy liquid commonly used are: â‘ tribromo methane (CHBr 3) or tetrabromoethane (C 2 H 2 Br 4) , a maximum density of 2.9 to 3, .0g /cm 3 . â‘¡ nematic liquid Du, based potassium iodide (KI) and mercury iodide (HgI 2) by K I: HgI 2 = 1: 1.24 ratio is formulated as an aqueous solution, the maximum density 3.2 g /cm 3 . 3 diiodomethane (CH 2 I 2 ) with a maximum density of 3.3g /cm 3 . â‘£ Kelieliqi solution, formic acid-based thallium (HCOOTl) and thallium malonate [2 CH 2 (COOTl)] formulated aqueous maximum density 4.25g /cm 3 . These heavy liquids are generally expensive, and some are harmful to the human body, so they are limited to laboratory use. The heavy suspension is used as a heavy medium in the industry. The heavy suspension is a two-phase fluid composed of finely pulverized solid particles and water. The large-density particles act to increase the density of the medium, so it is also called aggravation. FLOTATION weighting material is mainly of silicon iron, magnetite, galena and pyrite, their properties are shown in Table 27.
Table 27 is
commonly used for the nature of aggravation | Aggravated name | density g/cm 3 | Mohs hardness | Formulated as a suspension Density g/cm 3 | Recycling method |
| Ferrosilicon magnetite Galena Pyrite | 6.9 5.0 7.5 4.9 ~ 5.1 | 6 6 2.5 to 2.7 6 | 3.8 2.5 3.3 2.5 | Weak magnetic separation Weak magnetic separation Flotation Flotation |
The weighting should be high in density, low in value, easy to recycle and have no harmful effects on beneficiation. Ferrosilicon is a better weighting agent, and its silicon content is preferably 13%
to 18%
. The magnetic properties are strong and easy to pulverize, but the price is high. Magnetite, galena and pyrite are used for the aggravation of these minerals. The fineness requirement is less than 200%,
accounting for 60%
to 80%
. The galena has a high density, but the hardness is small and easy to mud; the magnetite and pyrite are low in price and high in hardness, but the density is small. At present, magnetite is widely used because it is convenient and less expensive to recover by magnetic separation than flotation.
According to the characteristics of molding, injection mold and thermoplastic plastic mold are divided into two types. According to the molding process, it can be divided into transfer mold, blow mold, casting mold, hot molding mold, hot pressing mold (compression mold), injection mold, etc. Among them, the hot pressing mold can be divided into three types, i.e., overflow, semi-overflow and non-overflow, and the injection mold can be divided into two types, i.e., cold runner mold and hot runner mold. It can be divided into two types: mobile type and fixed type.
Plastic Injection Accessories
Plastic Injection Accessories,Injection Molded Leakproof Accessories,Plastic Handles For Boxes,Black Plastic Handles,Plastic Injection Molding Service
Timeplex Industrial Limited , https://www.timeplexhk.com