Method for recovering valuable metals and simultaneously preparing ceramsite by roasting cyanide tailing

Abstract

A method for recovering valuable metals and simultaneously preparing ceramsite by roasting cyanide tailing belongs to the area of comprehensive recovery and high value utilization of metallurgical waste residue. In this method, cyanide tailings, bentonite, calcium chloride, coal powder and albite are mixed by ball milling according to certain weight ratio to get a mixture. After drying and roasting twice, dust is collected from the roasted ash, the obtained polymetallic ash is collected and treated. The secondary calcined material is cooled to obtain ceramsite. The invention volatilizes and recovers the valuable metal in the roasting and sintering process of cyanide tailings and directly prepares the ceramsite through reasonable batching, which achieves the effect of recycling cyanide tailings and high-value utilization, can create good economic and environmental benefits, and has significant effect of energy saving and consumption reduction.

Claims

1. A method for recovering valuable metals and simultaneously preparing ceramsite by roasting cyanide tailing, comprising the following steps: (1) ball milling: a mixture of the cyanide tailing, bentonite, calcium chloride, pulverized coal and albite with a weight ratio of 100:(5-10):(4-10):(1-7):(5-20) is obtained via ball milling; (2) prilling: the mixture obtained in step (1) is fed into a disc granulator for granulation, and raw material balls with particle size of 2-5 cm are obtained; (3) drying: the raw material balls obtained in step (2) are dried at 100-200 C. for 3-5 hours to obtain dried raw material balls; (4) primary roasting: the dried material balls obtained in step (3) are roasted at 700-900 C. for 0.5-3 hours to obtain primary calcined material and ash; (5) secondary roasting: the primary calcined material obtain in step (4) is roasted at 1050-1200 C. for 0.5-3 hours, secondary calcined material and ash is obtained; (6) dust collection: the ash obtained in steps (4) and (5) which contains polymetallic ash is collected and treated; (7) cooling: the secondary calcined material obtained in step (5) is cooled to obtain the ceramsite.

2. The method for recovering valuable metals and simultaneously preparing ceramsite by roasting cyanide tailing according to claim 1, wherein steps (4), (5) and (7) are carried out in the same roasting equipment.

Description

BRIEF DESCRIPTION OF THE APPENDED DRAWING

(1) FIG. 1 shows the process flow chart of the method of recovery valuable metals and simultaneously preparing ceramsite by roasting cyanide tailing.

PREFERRED EMBODIMENTS

(2) Embodiment 1

(3) (1) ball milling: the mixture of cyanide tailings, bentonite, calcium chloride, pulverized coal and albite is obtained by ball milling with a weight ratio of 100:5:4:1:5;

(4) (2) prilling: the mixture obtained in step (1) is fed into the disc granulator for granulation, and raw material balls with particle size of 2 cm are obtained;

(5) (3) drying: the raw material balls obtained in step (2) are dried under 100 C. for 3 h to obtain a dried material;

(6) (4) primary roasting: the dried materials obtained in step (3) are primary roasted, with the roasting temperature of 700 C. and the roasting time of 0.5 h to obtain primary calcined material and ash;

(7) (5) secondary roasting: the primary calcined material obtained in step (4) is roasted at high temperature, the roasting temperature is 1050 C., the roasting time is controlled as 0.5 h, secondary calcined material and ash is obtained;

(8) (6) dust collection: the ash obtained in steps (4) and (5) is treated with dust collection, and the obtained polymetallic ash is centralized and treated;

(9) (7) cooling: the secondary calcined material obtained in step (5) is cooled to obtain ceramsite.

(10) Through the method of this embodiment, the leaching content of several heavy metals in the finished ceramsite fired by cyanide tailings is: (mg/L): Ag:0.0015, Cu:0.043, Zn:0.0013, As:0.0014, Pb:0.0015, the content of Hg is lower than the detection limit; The physical properties of ceramsite are as follows: 1 h water absorption rate is 13%, bulk density is 1025 kg/m.sup.3, and cylinder compression strength is 11.5 MPa.

(11) Embodiment 2

(12) (1) ball milling: the mixture of cyanide tailings, bentonite, calcium chloride, pulverized coal and albite is obtained by ball milling with a weight ratio of 100:10:10:7:20;

(13) (2) rilling: the mixture obtained in step (1) is fed into the disc granulator for granulation, and raw material balls with particle size of 5 cm are obtained;

(14) (3) drying: the raw material balls obtained in step (2) are dried under 200 C. for 5 h to obtain a dried material;

(15) (4) primary roasting: the dried materials obtained in step (3) are primary roasted, with the roasting temperature of 900 C. and the roasting time of 3 h to obtain primary calcined material and ash;

(16) (5) secondary roasting: the primary calcined material obtained in step (4) is roasted at high temperature, the roasting temperature is 1200 C., the roasting time is controlled as 3 h, secondary calcined material and ash is obtained;

(17) (6) dust collection: the ash obtained in steps (4) and (5) is treated with dust collection, and the obtained polymetallic ash is centralized and treated;

(18) (7) cooling: the secondary calcined material obtained in step (5) is cooled to obtain ceramsite.

(19) Through the method of this embodiment, the leaching content of several heavy metals in the finished ceramsite fired by cyanide tailings is: (mg/L): Ag:0.001, Cu:0.041, Zn:0.0011, As:0.0012, Pb:0.0013, the content of Hg is lower than the detection limit; The physical properties of ceramsite are as follows: 1 h water absorption rate is 15%, bulk density is 1150 kg/m.sup.3, and cylinder compression strength is 12.5 MPa.

(20) Embodiment 3

(21) (1) ball milling: the mixture of cyanide tailings, bentonite, calcium chloride, pulverized coal and albite is obtained by ball milling with a weight ratio of 100:7:5:3:10;

(22) (2) rilling: the mixture obtained in step (1) is fed into the disc granulator for granulation, and raw material balls with particle size of 3 cm are obtained;

(23) (3) drying: the raw material balls obtained in step (2) are dried under 150 C. for 4 h to obtain a dried material;

(24) (4) primary roasting: the dried materials obtained in step (3) are primary roasted, with the roasting temperature of 800 C. and the roasting time of 1 h to obtain primary calcined material and ash;

(25) (5) secondary roasting: the primary calcined material obtained in step (4) is roasted at high temperature, the roasting temperature is 1100 C., the roasting time is controlled as 1 h, secondary calcined material and ash is obtained;

(26) (6) dust collection: the ash obtained in steps (4) and (5) is treated with dust collection,and the obtained polymetallic ash is centralized and treated;

(27) (7) cooling: the secondary roast obtained in step (5) is cooled to obtain ceramsite.

(28) Through the method of this embodiment, the leaching content of several heavy metals in the finished ceramsite fired by cyanide tailings is: (mg/L): Ag:0.001, Cu:0.047, Zn:0.001, As:0.0014, Pb:0.0017, the content of Hg is lower than the detection limit; The physical properties of ceramsite are as follows: 1 h water absorption rate is 12.4%, bulk density is 1035 kg/m.sup.3, and cylinder compression strength is 11.7 MPa.