Extraction, blasting

The process of extraction requires first smelting (to obtain the crude metal) and then refining. In smelting, iron ore (usually an oxide) is mixed with coke and limestone and heated, and hot air (often enriched with oxygen) is blown in from beneath (in a blast furnace). At the lower, hotter part of the furnace, carbon monoxide is produced and this is the essential reducing agent. The reduction reactions occurring may be represented for simplicity as ... 

The success of the process results from the fact that nowhere inside the furnace is heat extracted from the copper-saturated blast furnace buUion through a soUd surface. The problem of accretion formation (metal buUd-up), which has plagued many other attempts to estabUsh a copper dtossing operation of this type, does not arise. In the cooling launder, lead-rich matte and slag accumulate on the water-cooled plates, but these ate designed so that when they ate lifted from the buUion stream, the dross cracks off and is swept into the furnace via the cooled lead pot. 

Quarries that excavate soft stone, notably mad or chalk, do not dtiU or blast, but extract the stone usiag heavy-duty rippers and scrapers. In the Middle West and Florida, lake mads and soft coralline limestone are dredged ia a process much like stripmining. 

The Iron Bla.stFurna.ee, The reduction of iron oxides by carbon in the iron (qv) blast furnace is the most important of all extractive processes, and the cornerstone of all industrial economies. Better understanding of the reactions taking place within the furnace has made possible a more efficient operation through better preparation of the burden, higher blast temperature, and sometimes increased pressure. Furnace capacity has doubled since the 1800s, whereas coke consumption has been reduced by about half The ratio of coke to iron produced on a per weight basis is ca 0.5 to 1. 

Many nonferrous metals can be extracted by reduction smelting, eg, copper, tin, nickel, cobalt, silver, antimony, and bismuth. Blast furnaces are sometimes used for the smelting of copper or tin, but flash and reverberatory furnaces are more common for metals other than lead. 

Blast gates Adjustable sliding gates (dampers) on extract ductwork used to balance the system. 

Most of the criteria found in literature are extracted from Bowen et al. (1968). Diagrams of pressure versus duration are presented for various body positions in relation to the blast wave, from which the chance of survivability can be calculated. Those diagrams were combined in a pressure-impulse diagram, which is depicted in Figure C-1. The scaled overpressure P equals Plp, in which P is the actual pressure acting on the body, and po is the ambient pressure. The scaled impulse i equals ... 

Schiittung, /. pouring, etc. (see schUtten) blasting (Brewing) extract-yielding materials. 

The aim of the fust dimension breadth is to reveal sequence-function relationships by comparing protein sequences by sequence similarity. Simple bioinformatic algorithms can be used to compare a pair of related proteins or for sequence similarity searches e.g., BLAST (Basic Local Alignment Search Tool). Improved algorithms allow multiple alignments of larger number of proteins and extraction of consensus sequence pattern and sequence profiles or structural templates, which can be related to some functions, see e.g., under http //www. expasy.ch/tools/ similarity. 

Hybinette A process for extracting nickel from sulfide ores. The nickel ore that occurs in Canada is a mixture of the sulfides of nickel, copper, and iron. Several methods have been used to separate these metals. In the Hybinette process, the ore is first smelted in a blast furnace, yielding a nickel-copper matte (i.e., a mixture of their lower sulfides). This is roasted to remove sulfur and leached with dilute sulfuric acid to remove copper. The resulting crude nickel oxide is used as the anode of an electrochemical cell. The nickel deposits on the cathode, which is contained in a cloth bag. Precious metals collect in the anode slime. The process was invented by N. V Hybinette in 1904 and operated at the Kristiansand refinery, Norway, from 1910. 

Mansfield A process for extracting copper from sulfide ores by roasting with anthracite or coke and a silicious flux in a special blast furnace. 

O Historically, the extraction of a metal from its ore was known as reduction. One way to reduce iron ore on an industrial scale is to use a huge reaction vessel, 30 m to 40 m high, called a blast furnace. The reactants in a blast furnace are an impure iron ore, such as Fe203, mixed with limestone, CaC03, and coke, C, which is made from coal. The solid mixture is fed into the top of the blast furnace. A blast of very hot air, at about 900°C, is blown in near the bottom of the furnace. The following reactions occur. 

Flow of Two Fluids. The major applications are in absorption, extraction, and distillation, with and without reaction. Other applications, also quite important, are for shell-and-tube or double-pipe heat exchangers, and noncatalytic fluid-solid reactors (blast furnace and ore-reduction processes). 

Peroxide explosives are potent explosives that can be made starting from common and easy to obtain raw materials. The analysis of triacetone triperoxide (TATP) and hexamethylenetriper-oxidediamine (HMTD) was successfully carried out by HPLC-APCI-MS in a powder sample as well as in post-blast extracts originating from a forensic case [134]. After RP separation on a C18 column using a methanohwater (75 25 v/v) mobile phase containing ammonium acetate (2.5mM) at a 0.4mL/min flow rate, detection was carried out in positive ion mode. MS-MS analysis of [TATPh-NH4]+ and [HMTD - H]+ as precursor ions was necessary in order to achieve the required sensitivity in the analysis of postblast extracts (LOD 0.8 and 0.08 ng on column, respectively). 

Note C A 2-hour extraction period is allowed for Permissible, Straight, Semigelatin and Ammonia Dynamites. Four to six hours are required for Gelatin Dynamites and Blasting Gelatin... 

The most important deposits of sulphur in the world arc those of Louisiana and Texas, U.S.A., where //. Franck s method of extraction is followed.2 This obviates the formation of sulphur dioxide and at the same time yields a product of such a degree of purity (in some wells as high as 99-9 per cent.) as to be suitable in most cases for direct use. A boring is made in the earth down to the sulphur stratum so that a continuous pipe can pass thence to the surface the pipe consists of throe concentric tubes (see lig. 1). Superheated water, c.g. at 150" is forced down the annular spaces A, A, between the outer tubes, in order to melt the sulphur in the neighbourhood of the cud of the boring. A blast of heated air down the inmost tube, II, then causes the molten sulphur to be carried up between the two inner tubes to the surface, where it is collected.3... 

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