Extraction beryllium

R. S. Babu and C. K. Gupta, Beryllium Extraction - A Review, Mineral Processing and Extractive Metallurgy Review Vol. 4, p. 39,1988. 

A beryllium concentrate is produced from the leach solution by the counter-current solvent extraction process (10). Kerosene [8008-20-6] containing di(2-ethylhexyl)phosphate [298-07-7] is the water-immiscible beryllium extractant. The slow extraction of beryllium at room temperature is accelerated by warming. The raffinate from the solvent extraction contains most of the aluminum and all of the magnesium contained in the leach solution. 

The largest consumption of beryllium is in the form of alloys, principally the copper—beryllium series. The consumption of the pure metal has been quite cyclic in nature depending on specific governmental programs in armaments, nuclear eneigy, and space. The amount of beryllium extracted from bertrandite has ranged between 200 and 270 metric tons per year since 1986 (14). Small quantities of beryl were also processed during this period. 

Production, Use, and Recycling In the US, almost all beryllium is purified from a large deposit of bertrandite that occurs at Spor Mountain, Utah. While this ore only contains 0.6% beryllium, extraction of the metal from this ore is easier than the extraction of beryllium from beryl (14%... 

Lieben J, Metzner F. Epidemiological findings associated with beryllium extraction. Am Ind Hyg Assoc J 1959 20 504-508. 

Beryllium is added to copper to produce an alloy with greatly increased wear resistance it is used for current-carrying springs and non-sparking safety tools. It is also used as a neutron moderator and reflector in nuclear reactors. Much magnesium is used to prepare light nieial allo>s. other uses include the extraction of titanium (p. 370) and in the removal of oxygen and sulphur from steels calcium finds a similar use. 

Beryllium Oxide. Beryllium oxide [1304-56-9], BeO, is the most important high purity commercial beryllium chemical. In the primary industrial process, beryllium hydroxide extracted from ore is dissolved in sulfuric acid. The solution is filtered to remove insoluble oxide and sulfate impurities. The resulting clear filtrate is concentrated by evaporation and upon cooling high purity beryllium sulfate, BeSO 4H20, crystallizes. This salt is... 

Two other factors are noteworthy the deleterious effects on chemical and mechanical properties of small amounts of impurities residual from extraction of the metal, and its toxicity. The first of these factors is obviated by vacuum melting the raw metal (for purification) as an essential prerequisite to further processing. The toxicity of beryllium is essentially a pulmonary problem and great care must be taken in handling the finely divided metal or its compounds. In practice, this type of activity is usually carried out under well-ventilated conditions. Certain tolerance levels for atmospheric beryllium are now internationally accepted and merit careful study before work on beryllium is embarked upon. 

Beryllium is extracted from the main source mineral, the alumino-silicate beryl, by conversion to the hydroxide and then through either the fluoride or the chloride to the final metal. If the fluoride is used, it is reduced to beryllium by magnesium by a Kroll-type reaction. The raw metal takes the form of pebble and contains much residual halides and magnesium. With the chloride on the other hand, the pure metal is extracted by electrolysis of a mixture of fused beryllium chloride and sodium chloride. The raw beryllium is now dendritic in character, but still contains residual chloride. 

Other fluorinated derivatives of acetylacetone are trifluoroacetylacetone (CF3COCH2COCH3) and hexafluoroacetylacetone (CF3COCH2COCF3), which form stable volatile chelates with aluminium, beryllium, chromium(III) and a number of other metal ions. These reagents have consequently been used for the solvent extraction of such metal ions, with subsequent separation and analysis by gas chromatography [see Section 9.2(2)]. 

The number of reported applications to analytical determinations at the trace level appear to be few, probably the best known being the determination of beryllium in various samples. The method generally involves the formation of the volatile beryllium trifluoroacetylacetonate chelate, its solvent extraction into benzene with subsequent separation and analysis by gas chromatography..61... 

The complex fluoride process consists of roasting beryl with Na2[SiF ] (or NajfFeFg]) at 700-750°C and leaching the product with water to extract the soluble beryllium fluorides. A flow diagram summarizing this process is given in Scheme 2. 

Other methods reported for the determination of beryllium include UV-visible spectrophotometry [80,81,83], gas chromatography (GC) [82], flame atomic absorption spectrometry (AAS) [84-88] and graphite furnace (GF) AAS [89-96]. The ligand acetylacetone (acac) reacts with beryllium to form a beryllium-acac complex, and has been extensively used as an extracting reagent of beryllium. Indeed, the solvent extraction of beryllium as the acety-lacetonate complex in the presence of EDTA has been used as a pretreatment method prior to atomic absorption spectrometry [85-87]. Less than 1 p,g of beryllium can be separated from milligram levels of iron, aluminium, chromium, zinc, copper, manganese, silver, selenium, and uranium by this method. See also Sect. 5.74.9. 

Beryllium ore extraction has been on the increase recently. Data for the past 5 years are shown in Fig. 1 (1). This increase is connected... 

Between pH values of ca. 6 and 12 aqueous solutions hold very little dissolved beryllium because of the low solubility of Be(OH)2. When the pH is raised above 12, the hydroxide begins to dissolve with the formation of, first, Be(OH)3 and then, at even higher pH values, Be(OH) (52). The presence of these species in strongly alkaline solutions was confirmed by means of solvent extraction experiments (90) and infrared spectroscopy (31). A speciation diagram is shown in Fig. 7, which was constructed using the values of log /33 = 18.8 and log /34 = 18.6 critically selected from Table III. The diagram illustrates clearly the precipitation and dissolution of Be(OH)2. 

Halides other than fluoride form very weak complexes in aqueous solution there are no reliable equilibrium constants to be found in the literature. The solution chemistry of aqueous solutions of beryllium chloride, bromide, and iodide have been reviewed previously (9). Some evidence for the formation of thiocyanate complexes was obtained in solvent extraction studies (134). 

Copaux A method for extracting beryllium from beryl. The ore is heated with sodium flu-orosilicate at 850°C. Leaching with water dissolves the beryllium fluoride, leaving the silica and most of the aluminum fluoride as an insoluble residue. Addition of sodium hydroxide precipitates beryllium as the hydroxide. The process was invented by H. Copaux and has been in use in France since 1915 and in the United Kingdom since World War II. 

Copaux-Kawecki An improved version of the Copaux process for extracting beryllium from beryl, which permits recovery of the fluorine. Addition of ferric sulfate to the dilute sodium fluoride solution remaining after the separation of the beryllium hydroxide precipitates sodium tetrafluoroferrate, which is then used in place of sodium fluorosilicate. 

Fuse-quench Also called the Kjellgren-Sawyer process. A process for extracting beryllium from beryl. The beryl is fused at 1,600°C and then rapidly quenched by pouring through a water jet of high velocity. The glassy product is heated to 900°C to precipitate beryllia from its solid solution in silica, and then extracted with sulfuric acid. Operated by the Brush Beryllium Company, Cleveland, OH. 

Perosa A process for extracting beryllium from beryl. 

Some metals are extracted in electrolytic cells. In section 11.3, you saw the extraction of sodium from molten sodium chloride in a Downs cell. Other reactive metals, including lithium, beryllium, magnesium, calcium, and radium, are also extracted industrially by the electrolysis of their molten chlorides. 

Figure 4.18 shows the extraction of beryllium with HTTA into hexone as a function of the concentration of oxalate ions, Ox , in the aqueous phase. 

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