Germanium minerals

Germanium minerals are extremely rare but the element is widely distributed in trace amounts (like its neighbour Ga). Recovery has been achieved from coal ash but is now normally from the flue dusts of smelters processing Zn ores. 

Germanium minerals are extremely rare but the element is widely distribnted in trace amounts. Its abundance ratio is about 7 x 10 % and it is mainly associated with copper, zinc, lead, selenium, arsenic, silver, iron, and so on. There are twenty-one isotopes Ge, Ge, Ge, Ge, Ge are naturally occurring. Germaiuum is common in organisms, but it is not an indispensable trace element. In humans, it is nontoxic, but when it reaches 1000 ppm in animal s food, the growth of animals wifi be inhibited and 50% of them will die. 

Fluorspar occurs in two distinct types of formation in the fluorspar district of southern Illinois and Kentucky in vertical fissure veins and in horizontal bedded replacement deposits. A 61-m bed of sandstone and shale serves as a cap rock for ascending fluorine-containing solutions and gases. Mineralizing solutions come up the faults and form vein ore bodies where the larger faults are plugged by shale. Bedded deposits occur under the thick sandstone and shale roofs. Other elements of value associated with fluorspar ore bodies are zinc, lead, cadmium, silver, germanium, iron, and thorium. Ore has been mined as deep as 300 m in this district. 

Some elements found in body tissues have no apparent physiological role, but have not been shown to be toxic. Examples are mbidium, strontium, titanium, niobium, germanium, and lanthanum. Other elements are toxic when found in greater than trace amounts, and sometimes in trace amounts. These latter elements include arsenic, mercury, lead, cadmium, silver, zirconium, beryUium, and thallium. Numerous other elements are used in medicine in nonnutrient roles. These include lithium, bismuth, antimony, bromine, platinum, and gold (Eig. 1). The interactions of mineral nutrients with... 

Zinc minerals tend to be associated with those of other metals the most common ate zinc—lead or lead—zinc, depending upon the dominant metal, zinc— copper or copper—zinc, and base metal such as silver. Zinc does occur alone, most often in the northeastern district, and here, as elsewhere, recoverable amounts of cadmium (up to 0.5%) are present. Other minor metals recovered from zinc ores are indium, germanium, and thallium. 

Germanium was predicted as the missing element of a triad between silicon and tin by J. A. R. Newlands in 1864, and in 1871 D. I. Mendeleev specified the properties that ekasilicon would have (p. 29). The new element was discovered by C. A. Winkler in 1886 during the analysis of a new and rare mineral argyrodite, AggGeSfi " he named it in honour of his country, Germany. By contrast, tin and lead are two of the oldest metals known... 

Reference has been made earlier to scattered rare metals, the five most important members of this particular group being gallium, indium, thallium, rhenium, and germanium. A common feature of these metals is that they do not form commercially significant mineral sources of their own, but are invariably produced from the processing of other mineral sources. The description given here pertains to rhenium, and serves as one example of these dispersed metals. 

Although germanium was unknown, Mendeleev predicted the properties of the missing element (which he referred to as ekasilicon) based on the properties of other elements. While analyzing the mineral argyrodite, Winkler found that it contained about 7% of some element that had not been identified, 463... 

Organogermanium compounds can be mineralized by wet oxidative digestion for 4 h at 70°C, in aqueous potassium persulphate, at pH 12. After dilution to an adequate concentration germanium can be determined by ICP-AES (inductively coupled plasma atomic emission spectrometry)9. 

Occurrence. Germanium is widely dispersed, but only a few minerals have been isolated. Germanite Cu3(Ge,Fe)S4 and renierite (Cu,Fe,Ge,Zn,As)S were in the past the principal sources of germanium. Actually germanium is recovered as by-product of the zinc production. 

Neuere geochemische Untersuchungen und zahlreiche Mineral-analysen haben die Anschauungen liber die Geochemie des Germaniums nicht verandert. 

Germaniums main minerals are germanite, argyrodite, renierite and canfieldite, all of which are rare. Small amounts of germanium are found in zinc ore, as well as in copper and arsenic ores. It is known to concentrate in certain plants on Earth, particularly in coal commercial quantities are collected from the soot in the stacks where coal is burned. 

British mineralogist Charles Hatchett Soft metal found in the mineral columbite, along with iron and manganese combined with germanium it forms an excellent high-temperature superconductor. 

GaUium is widely distributed in nature, mostly found in trace amounts in many minerals including sphalerite, diaspore, bauxite, and germanite. It is found in aU aluminum ores. Gallium sulfide occurs in several zinc and germanium ores in trace amounts. It also is often found in flue dusts from burning coal. Abundance of this element in the earth s crust is about 19 mg/kg. Its average concentration in sea water is 30 ng/L. 

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