Material briquet

Die diameter Press rating Oil pressurizing pump Feed material Briquet size Production rate... 

DRI can be produced in pellet, lump, or briquette form. When produced in pellets or lumps, DRI retains the shape and form of the iron oxide material fed to the DR process. The removal of oxygen from the iron oxide during direct reduction leaves voids, giving the DRI a spongy appearance when viewed through a microscope. Thus, DRI in these forms tends to have lower apparent density, greater porosity, and more specific surface area than iron ore. In the hot briquetted form it is known as hot briquetted iron (HBI). Typical physical properties of DRI forms are shown in Table 1. 

Brown coals yield, on solvent extraction, 10—15% of a material that contains 60—90% light yellow or brown waxy substances. The remainder is a mixture of deep brown resinous and asphaltic substances. The yield may be increased by increasing the pressure during extraction, but this also adds dark colored dispersion products, and the resultant brown coal caimot be briquetted. 

Alternatively, anhydrous aluminum chloride may be hydroly2ed ia chilled dilute hydrochloric acid. Briquetting of the anhydrous material slows the reaction and the hydrogen chloride evolved may be recycled to aid precipitation of the hexahydrate. 

Cast-Iron Boring s. Several grades of cast-iron borings and drillings that are free of steel turnings, lumps, and msted material are called cast-iron borings. Some are suppHed in hot or cold briquetted form to specified densities. Oil and water limits may be specified also. 

Pellet Mills. Pellet mills differ from roU briquetting and compacting machines in that the particulates are compressed and formed into agglomerates by extmsion through a die rather than by squeezing as they are carried into the nip between two roUs. Several types of equipment that use the extmsion principle are available. The die may be a horizontal perforated plate with rollers acting on its upper surface to press material through the plate. 

Hot (500—700°C) bindedess briquetting of oxidized zinc and lead feed materials to replace sintering (see Size enlargement). 

The process for the thermal activation of other carbonaceous materials is modified according to the precursor. For example, the production of activated carbon from coconut shell does not require the stages involving briquetting, oxidation, and devolatilization. To obtain a high activity product, however, it is important that the coconut shell is charred slowly prior to activation of the char. In some processes, the precursor or product is acid-washed to obtain a final product with a low ash content (23,25). 

Roll presses can produce large quantities of materials at low cost, but the product is fess uniform than that from molding or tableting presses. The introduction of the proper quantity of material into each of the rapidly rotating pockets in the rolls is the most difficult problem in the briquetting operation. Various types of feeders have helped to overcome much of this difficulty. 

JVIA is available commercially in 99% purity in both molten (liquid, above 127°F) and solid forms (flakes, pellets, rod, or briquets). MAis often shipped in fiber drums or bags. Heated tank cars or trucks are used for liquid shipments. Because of the toxic fumes, the hazardous materials designation must be posted on all shipments. 

Demirbas, A. 1999. Evaluation of biomass materials as energy sources upgrading of tea waste by briquetting proeess. Energy Sourees 21 215-220. 

The MelDAS technology is a modified incineration process in which high temperatures destroy organic contaminants in soil and concentrate metals into fly ash. Details of the metals immobilization process can vary based on the specific application, but the essential steps are to combine the toxic-metal containing material with the appropriate amount of sorbent, to form this mixture into pellets or briquets placing the metal compounds into intimate contact with the sorbent, and to heat treat the pellets causing a reaction to form nonleachable metal compounds. The MelDAS process requires a sorbent. 

Through circulation dryers employ perforated or open screen bottom tray construction and have baffles that force the air through the bed. Superficial velocities of 150 ft/min are usual, with pressure drops of 1 in. or so of water. If it is not naturally granular, the material may be preformed by extrusion, pelleting, or briquetting so that it can be dried in this way. Drying rates are greater than in cross flow. Rates of 0.2-2 lb/(hr)(sqft tray area) and thermal efficiencies of 50% are realized. Table 9.7(d) has performance data. 

Most materials are briquetted or compacted by pressure alone. However, in some cases, a binder must be utilized to supplement the mechanical forces required for agglomeration. The binder has to be inert and non-contaminating to the material. Please state whether this approach would be permissible with your material. 

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