A process according to claim 2 in which the lime of step (c) is heated to substantially reduce the size of the particles and the hot, particulate lime is recycled to the fluidized bed. More particularly, it relates to the decomposition of the calcium nitrate so as to form nitrogen oxides from which additional nitric acid may be produced. When some oxygen ions penetrate concrete, calcium nitrite reacts with oxygen to be transformed into calcium nitrate.However, when all the calcium nitrite added during the mixing has been transformed into calcium nitrate, oxygen ions resume their attack on the reinforcing steel. Sie können Ihre Einstellungen jederzeit ändern. Water may be added to the autoclave through line 13, and nitric acid produced in the autoclave may be withdrawn through line "14. A portion of the solids withdrawn through line 15 may be passed through line 16 t0 fluo-solids regenerator 17 in which the solids are heated by combustion gases entering through line 18. "Anhydrous calcium nitrate melts at 836 ± 2 K and subsequent decomposition occurs in the liquid phase. Van Iperen Calcium Nitrate Anhydrous Horticultural Grade Plus is a highly pure Calcium fertilizer with a neglectable amount of ammonium, making it a top choice for soilless cultivation. The material to be decomposed is introduced into reactor 1 through line 3, while line 4 is provided for the withdrawal of gases from the upper portion of reactor 1. A process according to claim 2 in which the calcium nitrate is in a substantially anhydrous form to minimize the formation of nitric acid. The product gas stream withdrawn from above the fluidized bed will generally comprise nitrogen oxides. from 1-100 micrometer, Physical properties of inorganic compounds, Zylum Beteiligungsgesellschaft Mbh & Co. Patente Ii Kg, Process for the production of hydrogen fluoride, phosphoric anhydride, calcium polyphosphates and nitric acid, Preparing lime, useful for trapping carbon dioxide, comprises adding nitric acid to calcium carbonate to give calcium nitrate, and heating the calcium nitrate to a temperature greater than or equal to that at which it breaks down into lime, Method for separating nitrogen oxide e.g. The liquid phase comprising calcium nitrate melt is caused by the phase change, or melting, that occurs below the decomposition temperature. This excess oxygen can, if desired, be obtained by the use of a fluidizing gas comprising oxygen. It is within the scope of the present invention to inject the calcium nitrate into the decomposition zone in either solid or liquid form. The final concentration in the irrigation water depends on the amount of nutrients in the stock solution, the injection ratio and the amount of nutrients used in the water. Description of the prior art In the nitric acid acidulation of phosphate rock for the production of wet process phosphoric acid and phosphatic fertilizers, calcium nitrate is produced as a byproduct. If you are planning to use this product for open field fertigation, If you are planning to use this product for foliar application, © 2020 Dies geschieht in Ihren Datenschutzeinstellungen. The lime thus removed from the product gas stream is passed through air lock valve 112 onto screw conveyor 113 that discharges the collected lime for storage with the lime recovered from the bottom of decomposition chamber 106. Illustrative of the various inert solids that may be employed are silica, clay, calcium carbonate, calcium oxide, and mixtures thereof. Calcium Nitrate is a good source of both Calcium and Nitrate. 2,737,445. References Cited UNITED STATES PATENTS 2,714,550 8/1955 Miller 23-l58X 2,757,072 7/1956 Kapp et al. It is a further object of the present invention to provide a process for the decomposition of calcium nitrate in which the recovery of the nitrogen values therefrom is maximized. The cooling requirements upon reconstituting this material as aqueous nitric acid are correspondingly increased. While the spacial velocity will depend upon the fineness and density of the inert solids employed, the velocity will generally range from about 0.5 to about 3.0 feet per second. In order to avoid air pollution, the gas may be passed through a water scrubber. Lime is also produced as a solid by-product of the decomposition reaction. In view of the Well known and critical need in the industry for alternatives to the ever increasing need for sulfur, the present invention is of the greatest importance to producers of wet process phosphoric acid, phosphatic feritilizers and related agricultural and other products. Cl. In the fluidized operation of the present invention, it has been found that the particles of lime tend to grow in size during their retention in the decomposition zone. Better solids and gas flow through the kiln result. 1 is a diagrammatic arrangement of the apparatus that may be employed for carrying out an embodiment of the process herein described, the novel features of which are set forth in the appended claims; and. The calcium nitrate solids being decomposed may be those formed in the nitric acid acidulation of phosphate rock to form wet process phosphoric acid. The nitrogen values of the calcium nitrate, which are produced in the form of nitrogen oxides, can thus be recovered in a product gas stream containing a relatively high proportion of nitrogen oxides. The present invention, however, is directed to those instances in which it is necessary or desirable to recover the nitrogen values from calcium nitrate in a more economical form. The heat required for decomposition of the calcium nitrate can be furnished by heating the portion of the product gas stream to be recycled to the reactor. While the amount of carbon dioxide is not critical, the nitrogen oxide-containing atmosphere may conveniently contain 20% or more by weight CO although lesser quantities may also be employed. By-product calcium nitrate is decomposed in accordance with the present invention to produce a product gas stream containing nitrogen oxides from which additional nitric acid may readily be obtained. In addition, if the recovery of by-product calcium carbonate is desired in the embodiment in which the fiuidizing gas contains carbon dioxide, the temperature should not exceed the decomposition temperature of the calcium carbonate, i.e. The recovery of the nitrogen values from the solid calcium nitrate separated from the reaction mixture is an important factor in the economic significance of the overall process. 2 is a diagrammatic illustration of the apparatus that may be employed for carrying out an alternate embodiment of the process herein described. An improved process for the decomposition of calcium nitrate and utilization of decomposition products therefrom which comprises: (a) decomposing calcium nitrate in a fluidized bed decomposition zone, said bed comprising lime particles, to form nitrogen oxide gases and lime as decomposition products. In FIG. The by-product calcium nitrate is commonly obtained in the form of calcium nitrate tetrahydrate, although a lower hydrate or the anhydrous salt may be produced depending upon the operating conditions employed.