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    3.
    发明专利
    未知

    公开(公告)号：BR8705756A

    公开(公告)日：1988-05-31

    申请号：BR8705756

    申请日：1987-10-28

    Applicant: DEGUSSA

    Inventor： KNORRE HELMUT ,  LOROSCH JURGEN ,  FISCHER JOACHIM ,  GRIFFITHS ANDREW

    IPC: C22B11/08

    Abstract: Leaching of gold and/or silver from ores or ore concentrates in an aqueous alkaline cyanide solution with added hydrogen peroxide has so far not been used industrially, because it is uneconomical, i.e. the consumption of H2O2 and NaCN was unduly high. It has been found that the process can be made very economical and disadvantages of the conventional leaching technology can be avoided if the addition of the aqueous H2O2 solution is controlled via the concentration of the oxygen dissolved in the leaching solution, which contains 2 to 20 mg of O2 and preferably 7 to 13 mg of O2 per litre. Preferably, 0.5 to 5% by weight of H2O2 solutions are added under control. The process is applicable to agitation leaching and heap leaching, the H2O2 addition being controlled via measuring the O2 concentration in a measuring stream. At low consumption of H2O2 and NaCN, sometimes the gold yield is even increased and the leaching time is shortened.

    Process for preparing alkali metal cyanide and alkaline earth metal cyanide granules
    4.
    发明专利
    Process for preparing alkali metal cyanide and alkaline earth metal cyanide granules 未知

    公开(公告)号：AU721518B2

    公开(公告)日：2000-07-06

    申请号：AU5293098

    申请日：1998-02-04

    Applicant: DEGUSSA

    Inventor： SCHUTTE RUDIGER ,  ALT HANS CHRISTIAN ,  BECKER-BALFRANZ CATRIN ,  SAUER MANFRED ,  HIPPEL LUKAS VON ,  FEUER OLIVER ,  LOROSCH JURGEN

    IPC: C01C3/08 ,  C01C3/10

    Abstract: Preparation of alkali or alkaline earth metal cyanide granules involves spraying an aqueous alkali metal hydroxide solution or an aqueous alkaline earth metal hydroxide suspension onto a fluidised product seed bed at 100-250 degrees C in a fluidised bed spray granulation reactor which is supplied with a hydrogen cyanide-containing gas in amount ≥ 1 mol HCN per metal equivalent, the introduced and formed water being evaporated by the fluidising gas supplied at 110-500 degrees C. Also claimed are sodium or potassium cyanide granules having a spherical particle shape with a smooth or raspberry-like surface structure, 0.1-20 mm particle diameter for 99 wt.% of the granules, ≥ 600 g/dm bulk density, less than 1 wt.% wear measured by the roller wear test (Erwaka TAR wear tester, 20 g sample, 60 minutes, 20 rpm.) and a clumping index of NOTGREATER 4 (measured by 14 day 10g load application onto a 100 g sample in a 5.5 cm inside diameter cylinder), the novelty being that the alkali metal carbonate content is less than 0.5 wt.% and the alkali metal formate content is less than 0.3 wt.%, the alkali metal in these by-products being the same as that in the cyanide. Preferably, the total alkali metal carbonate and alkali metal formate content is less than 0.4 wt.% and the granules are prepared by the above process using reaction gas from a BMA process and superheated steam as fluidising gas.

    ALKALI CYANIDE-GRANULATES AND PROCESS FOR THEIR PRODUCTION
    5.
    发明专利
    ALKALI CYANIDE-GRANULATES AND PROCESS FOR THEIR PRODUCTION 未知

    公开(公告)号：SK133693A3

    公开(公告)日：1994-06-08

    申请号：SK133693

    申请日：1993-11-29

    Applicant: DEGUSSA

    Inventor： RIEMENSCHNEIDER HERBERT ,  ALT CHRISTIAN ,  CLAUS MARTIN ,  LOROSCH JURGEN ,  LEUTNER JOSEF ,  MONCH HEINZ

    IPC: B01J2/04 ,  B01J2/16 ,  C01C3/10

    Abstract: The invention relates to new alkali cyanide granules based on sodium cyanide or potassium cyanide and also a process for the preparation thereof. Commercial alkali cyanide granules comprise irregular particles: disadvantages are, in particular, the tendency to form dust and lumps. Alkali cyanide granules of the invention have practically no abrasion and a reduced tendency to form lumps. The granules are characterised by essentially spherical particles, particle diameters in the range from 0.1 to 20 mm, a bulk density above 600 g/dm , an abrasion of less than 1% and a caking index of at most 4. The granules can be prepared by fluidised-bed spray granulation, by an aqueous solution containing an alkali cyanide being sprayed on alkali cyanide nuclei in a fluidised bed and water being evaporated.

    6.
    发明专利
    未知

    公开(公告)号：MX169904B

    公开(公告)日：1993-07-30

    申请号：MX895987

    申请日：1987-10-23

    Applicant: DEGUSSA

    Inventor： FISCHER JOACHIM ,  KNORRE HELMUT ,  GRIFFITHS ANDREW ,  LOROSCH JURGEN

    IPC: C22B11/08

    Abstract: Leaching of gold and/or silver from ores or ore concentrates in an aqueous alkaline cyanide solution with added hydrogen peroxide has so far not been used industrially, because it is uneconomical, i.e. the consumption of H2O2 and NaCN was unduly high. It has been found that the process can be made very economical and disadvantages of the conventional leaching technology can be avoided if the addition of the aqueous H2O2 solution is controlled via the concentration of the oxygen dissolved in the leaching solution, which contains 2 to 20 mg of O2 and preferably 7 to 13 mg of O2 per litre. Preferably, 0.5 to 5% by weight of H2O2 solutions are added under control. The process is applicable to agitation leaching and heap leaching, the H2O2 addition being controlled via measuring the O2 concentration in a measuring stream. At low consumption of H2O2 and NaCN, sometimes the gold yield is even increased and the leaching time is shortened.

    Alkali metal cyanide granulates and a process for their preparation
    9.
    发明专利
    Alkali metal cyanide granulates and a process for their preparation 未知

    公开(公告)号：AU668778B2

    公开(公告)日：1996-05-16

    申请号：AU5215293

    申请日：1993-12-03

    Applicant: DEGUSSA

    Inventor： RIEMENSCHNEIDER HERBERT ,  ALT CHRISTIAN ,  CLAUS MARTINA ,  LOROSCH JURGEN ,  LEUTNER JOSEF ,  MONCH HEINZ

    IPC: B01J2/04 ,  B01J2/16 ,  C01C3/10

    Abstract: The invention relates to new alkali cyanide granules based on sodium cyanide or potassium cyanide and also a process for the preparation thereof. Commercial alkali cyanide granules comprise irregular particles: disadvantages are, in particular, the tendency to form dust and lumps. Alkali cyanide granules of the invention have practically no abrasion and a reduced tendency to form lumps. The granules are characterised by essentially spherical particles, particle diameters in the range from 0.1 to 20 mm, a bulk density above 600 g/dm , an abrasion of less than 1% and a caking index of at most 4. The granules can be prepared by fluidised-bed spray granulation, by an aqueous solution containing an alkali cyanide being sprayed on alkali cyanide nuclei in a fluidised bed and water being evaporated.

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