Odda process

In the Odda process, used by Det Norske Zinkkompani in Norway in collaboration with Boliden Kemi, the gases are subjected to scrubbing with a mercuric chloride solution which reacts with mercury, yielding insoluble mercurous chloride this can be separated by filtering. 

One process modification that overcomes these difficulties uses only nitric acid for acidulation the extraction slurry is cooled to crystallize calcium nitrate, which then is removed by centrifugation. This process is referred to as the Odda process. The calcium nitrate byproduct is either sold as a fertilizer or converted to co-product ammonium nitrate. The extraction slurry, with its lowered calcium content, then is ammoniated and granulated. 

Most of the nitric acid is utilized in the form of 50 to 70% acid for the manufacture of nitrogen-containing fertilizer, particularly ammonium nitrate. Ammonium nitrate is also used as an explosive e.g. in mining, due to its low explosion temperature (safety explosive). Other industrially important nitrates are sodium nitrate, a speciality fertilizer and oxidizing agent in the glass and enamel industries, and calcium and potassium nitrates, which are also used as fertilizers. Nitric acid is also utilized in the digestion of raw phosphate (Odda process, which is not operated in the USA, see Section 2.1.2.4) ... 

Separation (partial) of the calcium nitrate from the digestion mixture by crystallizing out at low temperatures as its tetrahydrate. The calcium nitrate separated can be converted with ammonia/carbon dioxide to a mixture of calcium carbonate and ammonium nitrate (lime ammonium nitrate) (Odda process)... 

NORWEGIAN CAPITALISTS AND THE FERTILISER BUSINESS THE CASE OF HAFSLUND AND THE ODDA PROCESS ... 

It is ironic that the Odda process is almost forgotten, even in Norway. This is especially so when we consider that although the electrochemical fixation of nitrogen was a scientific landmark that has been justly celebrated, laid the foundation for the largest Norwegian industrial enterprise for most of this century (Norsk Hydro), and made its... 

Odda Smelteverk never used the process itself, however, but licenced it to I.G. Farben, Staatsmijneh of the Netherlands, as well as to Norsk Hydro. Odda stayed in its oldest businesses, that of producing calcium carbide and cyanamide. Neither did Odda s owner, the Hafslund group, use the Odda process. In 1937 it sold Odda Smelteverk along with the Odda process to the British Oxygen Company. 

The aim of this paper is to understand the fate of the Odda process, and explain why it was invented at but never used by Odda Smelteverk and the Hafslund group. To achieve this, the paper is divided into three parts. The first part discusses the Hafslund group s strategic intent with respect to Odda Smelteverk and the Odda process. The second part looks into the Odda process itself, while the third part discusses why Hafslund did not exploit the Odda process. 

The invention of the Odda process at Odda Smelteverk was thus no coincidence. It was the company s strategy to develop this large producer of the nitrogen fertiliser cyanamide also as a producer of new fertilisers. Odda produced 57,000 tons of cyanamide in 1928, mostly for export, and it had been experimenting with new processes for several years, and filing relevant patents, when it discovered an economical way to produce phosphoric acid. ... 

It all benefitted Norsk Hydro, however. While Odda was completely honest about its technical knowledge, Norsk Hydro tried to circumvent the Odda process patent. After negotiations fell through in 1933, three leaders of Odda summed up their bitter experiences Norsk Hydro had not made any serious offer, but seemed to have wanted to postpone the matter and to get hold of all possible information, information that is now used to circumvent the Odda process. " " Even though Norsk Hydro clearly exploited the economic difficulties of Odda at the time, it is possible to understand why, since Odda s real plans had been to collaborate with American Cyanamid Company, in all probability as a competitor to Norsk Hydro. In any case, Norsk Hydro was in a very vulnerable position itself, also hit by the crisis it was only in 1929 that it completed restructuring to produce nitrogen fertiliser by the Haber-Bosch process. In the end, Odda did very little. Odda Smelteverk was sold to the British Oxygen Company in late 1937, and the Odda process was licenced to I.G. Farben in 1938, to Dutch Staats Mijnen in 1939, and eventually to Norsk Hydro after the war. 

The two commercially important nitrophosphate processes differ in the way they solve the problem of phosphate water solubility caused by the presence of calcium nitrate in the slurry resulting from the reaction of phosphate rock vnth nitric acid. The first process, historically, is the Odda process wherein calcium nitrate is precipitated and separated. Tlie mixed acid process does not separate the calcium nitrate the phosphate water solubility is increased by adding phosphoric acid to decrease the CaO P205 ratio. 

The principal developers of the Odda process (Figure 13.2) have been BASF and Norsk Hydro. In the following account of the Odda process, the descriptions of the dissolving and crystallization sections were originally written for the BASF process [3]. The BASF and Norsk... 

Figure 13.3. Inert Removal in BASF Odda Process.

Several process and equipment alternatives are used in practice of the Odda process Table 13.1 gives the unit process consumption values for an average Odda nitrophosphate plant. 

Figure 13.6. Odda-Process CN-Conversion/ CAN-Granulation Sequence.

Nitrophosphate products, either granular or prilled, contain calcium in the NP(K) grades and in the ammonium nitrate coproduct (see Chapter 13). NPK grades such as 13-13-13 retain some of the calcium originally in the PR because the calcium nitrate is neyer completely removed in the Odda process crystallization step. The re ual calcium is converted primarily to dicaldum phosphate when ammoniation is carried out to produce the NPK products. Tlie separated crystalline calcium nitrate is dissolved and converted to ammonium nitrate solution and solid calcium carbonate by addition of ammonia and carbon dioxide. The ammonium nitrate solution... 

Inorganic fertilizer is often synthesized using the Haber-Boseh proeess, whieh produees ammonia as the end produet. This ammonia is used as a feedstoek for other nitrogen fertilizers, sueh as anhydrous ammonium nitrate and urea. These eoneentrated produets may be diluted with water to form a eoneentrated liquid fertilizer. Ammonia ean be eombined with roek phosphate and potassium fertilizer in the Odda Process to produee eompound fertilizer. 

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