公开(公告)号：DE1518353C3

公开(公告)日：1973-11-22

申请号：DE1518353

申请日：1964-11-12

Applicant: STAMICARBON N.V., HEERLEN (NIEDERLANDE)

Inventor： SUVERKROPP, GEERTRUDES HERMAN, BEEK (NIEDERLANDE)

IPC: A23K1/16 ,  C07C99/12

公开(公告)号：DE1567830C3

公开(公告)日：1973-10-04

申请号：DE1567830

申请日：1965-03-18

Applicant: STAMICARBON N.V., HEERLEN (NIEDERLANDE)

Inventor： DEROOIJ, ABRAHAM HERMANUS, GELEEN ,  ELMENDORP, JAN, BRUNSSUM

IPC: C01B25/28 ,  C01B25/40 ,  C01B25/46 ,  C05B1/04 ,  C05B7/00 ,  C05B11/06 ,  C01B25/26

Abstract: Water-soluble calcium phosphate is prepared by decomposing phosphate rock with excess HNO3 of e.g. 45-65% concn., extracting this decomposition liquor with a polar organic solvent which is poorly immiscible with H2O to remove most of the acids and part of the Ca(NO3)2, extracting this extractor soln. with a polar organic solvent poorly immiscible with H2O which preferentially dissolves HNO3, such that Ca(NO3)2 and H3PO4 remaining in the solution are converted to Ca(H2PO4)2 MH2PO4, where M is alkalimetal or NH4, may be prepared by adding M2SO4 to the aqueous extractor solution as above, separating the pptd. gypsum, and extracting the HNO3 as above. The decomposition liquor may be extracted by an ether or ketone but preferably by an aliphatic alcohol having 4-6 carbon atoms in the molecule. The HNO3 may be extracted by an aliphatic ketone or ether. Some Ca(NO3)2 may be removed from the decomposition liquor by partial crystallization before extraction. The process may be carried out in a continuous manner by recycling the organic solvent from the first extraction stage after washing with H2O; crystallizing the phosphate from the aqueous extractor soln. after removal of HNO3 therefrom, and recycling the phosphate mother liquor to the HNO3-extraction stage, and neutralizing the HNO3-containing solvent, e.g. with aq. NH3, and recycling this solvent after removal of the nitrate produced. A flow-diagram for such a continuous process is described.

公开(公告)号：MY6700126A

公开(公告)日：1967-12-31

申请号：MY6700126

申请日：1967-12-31

Applicant: STAMICARBON N.V.

IPC: C07C273/04 ,  C07C126/02

Abstract: In the preparation of urea by a synthesis from NH3 and CO2, the urea melt produced which contains ammonium carbamate is stripped therefrom with carbon dioxide at a pressure of at least 10 atmospheres. The ammonium carbamate which is expelled as NH3 and CO2, together with the CO2 used for stripping are used for the urea synthesis. Part of the total carbon dioxide used may be reacted with ammonia and the remainder of the carbon dioxide is used in the stripping, condensed with the stripped gas and returned to the reactor as carbamate solution or suspension, or alternatively the gas mixture from the stripping treatment may be fed directly to the reactor (Figs. 1 and 2). As a further alternative the stripping treatment takes place in the reactor (Fig. 3) by feeding in the components at different points and discharging the melt produced in counter-current contact with the introduced carbon dioxide.

公开(公告)号：GB986428A

公开(公告)日：1965-03-17

申请号：GB2755061

申请日：1961-07-28

Applicant: STAMICARBON N.V.

IPC: B03B5/44 ,  B07B1/00

Abstract: 986,428. Washing granular material; spray producers. STAMICARBON N.V. July 28, 1961 [July 30, 1960; Sept. 16, 1960], No. 27550/61. Headings B2F and B2H. Coal is washed free of magnetite, which was used in suspension to free the coal from shale, by rinsing it with streams of water while it is supported on a screen, the kinetic energy of the water streams being insufficient to disturb the coal and its quantity being insufficient to form pools on the screen. As shown in Fig. 1, the coal is moved as a bed along a reciprocated screen 2 and rinsing water is provided from above by an apertured tank 4 the level in which is controlled by a float valve 6 and 7. The rinsing water leaves the tank through apertures 11 and flows on to plates 12, see Fig. 2, where it is broken up by corrugations 14 to form thin trickles 17. Instead of forming the corrugations in the sheet 12 a separated corrugated sheet may be welded underneath the sheet 12. In place of corrugations the sheet 12 may have a saw-tooth edge. The screen has ribs 3 at intervals along its length to provide a minimum of relative motion between the coal particles. Instead of ribs the screen may be in steps, preferably rounded to allow the coal to fall over smoothly. Fig. 5 shows the diagram of a process of separating coal from shale with the use of a magnetic suspension and means to recover the magnetite. Coal containing shale is fed at A, with a magnetite suspension at B, into a mixing tank 21 from which the mixture is fed to a cyclone washer 23 which separates the coal and shale fractions into paths 24 and 25, respectively. The coal is shot down a curved screen 26 of the kind described in Specification 791,520 and hoppers 27 and 29 collect very fine coal and undiluted magnetite suspension which is recirculated from a tank 32 back to the mixing tank 21. The coal with adhering magnetite particles is now rinsed on a reciprocating screen 34, as described above with reference to Figs. 1 and 2, and the clean coal is extracted at C. Sprinklers 35 and 36 are employed with pure water supplied from a main W. Sprinkler 36 receives nothing but pure water and gives a final rinse. Sprinkler 35 also consumes recirculated water. The diluted magnetite suspension and fine coal collected beneath screen 34 is shot on to a further curved screen 39 and passes to a magnetic separator 41 which has an output of coal at D and of magnetite at 43. The dilute magnetite suspension is thickened in a trough 45, water overflowing from this trough being recirculated to the sprinkler 35 and the thickened magnetite suspension being recirculated to the mixer 21. Shale ejected from the cyclone washer at 25 is treated in the same way as the coal to reclaim the magnetite suspension. The necessary plant is a duplicate of that employed for the coal and is shown with the same references and a superscript dash.