Chile, nitrate from

Potassium Nitrate. Potassium nitrate, known but Httle used as a fertilizer for many years, may be reclaimed as a by-product of the production of sodium nitrate from natural deposits of caflche in Chile. KNO also has been produced by the double decomposition reaction between sodium nitrate and potassium chloride ... 

Farben, said Von Knieriem, had two weapons sole scientific knowledge of the latest chemical developments in the explosives field, and a monopoly on the intermediate products that Dynamit A.G. couldn t do without. If Dynamit A.G. bought nitrates from Chile, their violation of the Versailles Treaty would be obvious to the rest of the world. And in Germany, Farben had a complete monopoly on synthetic nitrates. 

Guggenheim A process for extracting sodium nitrate from caliche, a native sodium nitrate found in Chile. The ore is leached at 40°C with water containing controlled concentrations of magnesium and calcium sulfates. Operated on a large scale in Chile. See also Shanks. 

Phase behavior 1n concentrated aqueous electrolyte systems is of interest for a variety of applications such as separation processes for complex salts, hydrometal 1urgical extraction of metals, interpretation of geological data and development of high energy density batteries. Our interest in developing simple thermodynamic correlations for concentrated salt systems was motivated by the need to interpret the complex solid-liquid equilibria which occur in the extraction of sodium nitrate from complex salt mixtures which occur in Northern Chile (Chilean saltpeter). However, we believe the thermodynamic approach can also be applied to other areas of technological interest. 

Before World War I, tbe main source of nitrates for human use was from large deposits of bird droppings in Peru and sodium nitrate from Chile. These sources were becoming scarce and expensive. Then Fritz Haber (1868-1934), a lecturer in a technical college in Germany, began to experiment with ways to manufacture ammonia. Haber knew that ammonia could he easily converted to nitrates and other useful nitrogen... 

Process technology and chemical engineering as we understand it today began with the successful realization of the technical ammonia synthesis. Continuous production with high space velocities and space yields combined with the ammonia oxidation process developed immediately thereafter enabled chemical industry for the first time to compete successfully with a cheap natural bulk product, namely, sodium nitrate from Chile. The synthesis of ammonia thus became exemplary for all subsequent chemical mass production processes. 

The significance of Haber s discovery was soon apparent. World War I began in 1914 in Europe. Very soon, Germany was no longer able to get nitrates from Chile. Nitrates were essential to the war effort for making explosives. But ships cartying nitrates from Chile to Germany were usually not able to get across the Atlantic Ocean. 

However, nitrates can be made from ammonia using the Haber process. Germany was then able to make all the ammonia it needed. The ammonia was converted to nitrates for explosives. So a lack of nitrates from Chile did not stop the German war machine. Instead, Germany went on fighting for another four years against countries such as France and Great Britain, who were later joined by the United States. 

Statistics.—The shipments of sodium nitrate from Chile and Peru are rapidly increasing, as the following figures show —... 

Preparation of Ammonium Nitrate by the Ammonia Soda Process.—In 1875 Gerlach (English Patent, 2,174) attempted to produce ammoninm nitrate from ammonium carbonate and Chile saltpetre according to the equation —... 

Tiie new method then will be at a disadvantage of 8 per ton of exportable nitrate from the start and must produce at a cost of 8 less per ton before production by this method can compete evenly with the older officinas. Any reduction in cost greater than 8 per ton w ill be that much to the advantage of the new method. From this it can be seen that not too great an advantage for Chile nitrate is to be expected from new methods of operation even though the old methods seem very crude. 

The preceding chapters indicate tliat from tlie present viewpoint at least the nitrogen source of the future will be the direct synthetic ammonia process for the fixation of atmospheric nitrogen. Chile nitrate, the arc process and the cyanamide process are all gradually but nevertheless efi ectively being displaced as sources of supply by the synthetic ammonia process. 

FlXAl ION OF ATMOSI HFRIC NITROGEN ammonia oxidation and from Chile nitrate, as follows ... 

If the cost of ammonia is considered as being as high as 6 cents per pound and Chile nitrate taken at the present quotation of 2.25 per 100 pounds, the cost of 95 pel cent nitric acid as worked out from this table is 59.96 per ton tlirough ammonia oxidation and 63.90 through Chile nitrate. 

From these figures it can be seen that fixed atmospheric nitrogen not only supplied the increased demand of 100,000 tons of nitrogen per year, but it has also made up the difference due to the falling off of Chile nitrate. This decrease in Chile nitrate amounted to over 50,000 tons of nitrogen per year for the past three years so that the Increase In fixed atmospheric nitrogen has been approximately... 

Fixed atmospheric nitrogen and more especially the direct synthetic ammonia process is fast approaching the position once enjoyed by Chile nitrate, but it can never from present indications actuary achieve that position. Ammonia it is believed will always be produced as a by-product of the operation of the coke ovens. The production of by-product ammonia will increase, but it is believed its increase w lll be very slow. 

Ch I la sa Itpetre A commercial mineral largely composed of sodium nitrate from the cdiche deposits in Chile. Before the ammonia-oxidation process for nitrates most imported Chilean saltpetre was used... 

Both Liebig, in the book he pubhshed in 1840," and Lawes, in his work at Rothamsted in 1845," recognised that nitrogeneous substances such as ammoiua or nitrate were essential for healthy plant growth. Lawes, in particular, stressed that additional nitrogen in the form of mineral fertilisers would be required. The nitrogen problem had become widely recognised as a serious issue towards the end of the nineteenth century, since by 1890, it was clear that the available quantities of sodium nitrate from Chile, Chile saltpeter, would not be sufficient to meet the anticipated future demand. It was equally clear that other sources of supply would soon be required. 

Most iodine produced commercially comes from the sodium iodate(V) remaining after sodium nitrate has been crystallised from Chile saltpetre. The iodatefV) is first reduced to iodide by blowing sulphur dioxide into the solution (or by addition of sodium sulphite) ... 

Mineral Deposits. The only iodine obtained from minerals has been a by-product of the processing of nitrate ores in Chile. CaUche occurs in the Atacama desert of Northern Chile and west of the Andes mountains. The Atacama desert is known as the driest of the world s deserts, where measurable (>1 mm) rainfalls may be as infrequent as once every 5—29 years (58). The caUche deposits occur in an area averaging 700 km (north—south) by 30 km (east—west). The iodine may total over 5 x 10 t (59). 

Potassium nitrate, essential in the manufacture of black gun powder, was produced by the Chinese, who had developed gun powder by the tenth century AD. The process involved the leaching of soil in which nitrogen from urine had combined with mineral potassium. By the early 1800s, potassium nitrate had become a strategic military chemical and was stiU produced, primarily in India, by using the ancient Chinese method. The caUche deposits in Chile are the only natural source of potassium nitrate (2). These deposits are not a rich source of potassium nitrate, purifying only to about 14% as K O. 

Among the properties sought in the solvent are low cost, avadabihty, stabiUty, low volatiUty at ambient temperature, limited miscibility in aqueous systems present in the process, no solvent capacity for the salts, good solvent capacity for the acids, and sufficient difference in distribution coefficient of the two acids to permit their separation in the solvent-extraction operation. Practical solvents are C, C, and alcohols. For industrial process, alcohols are the best choice (see Amyl alcohols). Small quantities of potassium nitrate continue to be produced from natural sources, eg, the caUche deposits in Chile. 

The Chilean nitrate deposits are located in the north of Chile, in a plateau between the coastal range and the Andes mountains, in the Atacama desert. These deposits are scattered across an area extending some 700 km in length, and ranging in width from a few kilometers to about 50 km. Most deposits are in areas of low rehef, about 1200 m above sea level. The nitrate ore, caUche, is a conglomerate of insoluble and barren material such as breccia, sands, and clays (qv), firmly cemented by soluble oxidized salts that are predominandy sulfates, nitrates, and chlorides of sodium, potassium, and magnesium. Cahche also contains significant quantities of borates, chromates, chlorates, perchlorates, and iodates. 

SQM Nitratos (Chile) operates two sodium nitrate plants in northern Chile Pedro de Valdivia and Mama Elena, about 30 km distant from one another. The caUche is mined in open-pit areas. A solar evaporation plant, Coya Sur, Hes in between. A flow sheet of the processing operations for sodium nitrate production is shown in Figure 2. 

As of 1996 world production of sodium nitrate was about 520,000 metric tons annually. Of this quantity, some 450,000 t (86%) are produced in Chile from natural deposits by SQM Nitratos and distributed worldwide by several affOiates, eg, Chilean Nitrate Corporation in the United States and Nitrate Sales International in Belgium. The remainder, ca 70,000 t, is manufactured mainly in Europe, Japan, and Russia, generally as a by-product of nitric acid production. Additionally, China is known to manufacture some unknown but significant volumes of sodium nitrate for domestic use. 

Ores of nitrogen are relatively rare. The best mineral is sodium nitrate, NaNOj, found in large deposits in Chile. We now prepare the nitrogen compounds we desire from the nitrogen of the... 

Production as practiced in Chile consists of leaching residues from their Na nitrate operation to produce a weak brine of K nitrate which is coned by solar evapn When the proper concn of K nitrate is achieved it is recovered by crystn (Ref 14)... 

Na nitrate occurs native in large deposits in the rainless districts of Chile, hence it is often called Chile saltpeter or Chile niter . The Na nitrate in the deposits constitutes from 20 to 50% in a distinct stratum of earth known as caliche . The caliche is crushed and lixiviated in large tanks of w heated by steam. The settled soln is run off to crystallizers, where crude nitrate separates, the mother liquors being run back to the lixiviators. The crysts are washed with a little w and dried in the sun they contain 95—96% Na nitrate (Ref 1)... 

Karl Bosch (1874-1940) and Alwin Mittasch (1869-1953) of Badische Anilin- und Soda-Fabrik eliminated the nitrate shortage that occurred after the British sea blockade effectively cut off the nitrate supply from Chile. By May of 1915, they had successfully developed at their Oppau Plant an industrial-scale process for oxidizing ammonia. Their process converted the large quantities of synthetic ammonia produced by the Haber process to nitric acid and other nitrates that were essential for fertilizers and explosives. (10)... 

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