Method for preparing iron oxide ore reduction roasting green ball by using iron selection tailings

Abstract

The invention provides a method for preparing an iron oxide ore reduction roasting green ball by using iron selection tailings. The method mainly comprises the following processing steps: (1) crushing and milling weakly magnetic iron ore, casting away a part of qualified tailings in advance by strong magnetic separation, thus obtaining a rough concentrate product of iron oxide ore; (2) carrying out grain size segregation on the qualified tailings obtained in the step (1), thus obtaining fine grained tailings products; (3) adding fine grained tailings which is 2-8% of mass of the rough concentrate and pulverized coal which is 1-5% of mass of the rough concentrate to the rough concentrate, and then evenly mixing the materials; and (4) feeding the evenly mixture into a ball-making plate through a belt, adding water for pelletizing, so as to obtain the iron oxide ore reduction roasting green ball product; and carrying out reduction roasting reduction in roasting equipment. According to the method, tailings casted away by strong magnetic separation are taken as a pelletizing binder, waste resources are fully utilized, iron oxide in the tailings can be properly recovered, and no bentonite or other binders need to be purchased, so that the production cost is effectively reduced.

Description

technical field

[0001] The invention belongs to the technical field of iron metallurgy, and relates to a method for producing iron oxide ore reduction roasting green pellets by utilizing iron beneficiation tailings. Background technique

[0002] With the rapid expansion of the scale of domestic iron and steel enterprises, the contradiction of insufficient iron ore resources has become increasingly serious. On the one hand, iron and steel enterprises expand imports and invest in foreign mines, and on the other hand, they speed up the development of domestic ores. Due to the high cost of imported ores, more and more enterprises choose the latter. Iron ore that is poorer and more difficult to select will also come into the eyes of developers, and there are a large number of iron oxide ores that are weakly magnetic. One of the important utilization ways of this part of iron ore is reduction roasting-magnetic separation.

[0003] Weak magnetic iron oxide ore refers to the sing...

Examples

Embodiment 1

[0026] A method for making iron oxide ore reducing and roasting green pellets by using iron beneficiation tailings, comprising the following process steps:

[0027] (1) Crush and grind the weakly magnetic iron oxide ore until the particle size is -200 mesh, accounting for 60-70%, through strong magnetic separation (selection parameters: magnetic field strength 0.8-1.2T, turntable speed 5 rpm, rinse water 20-25L / min) discard the qualified tailings with an iron grade below 13% in advance to obtain iron oxide ore rough concentrate products with an iron grade of 40.6%, and filter the obtained rough concentrate to a moisture content of 8- 13%;

[0028] (2) Classify the qualified tailings after the strong magnetic separation in step (1) through a cyclone to obtain a fine-grained tailings product with -400 mesh greater than 80%;

[0029] (3) Add fine-grained tailings equivalent to 2% of the mass of coarse concentrate and 3% coal powder into the rough concentrate, and then mix the ma...

Embodiment 2

[0032] The difference between embodiment 2 and embodiment 1 is:

[0033] In step (1), the iron grade of the obtained iron ore coarse concentrate product is 41.2%;

[0034] In step (3), fine-grained tailings equivalent to 5% of the mass of the coarse concentrate and 5% coal powder are mixed into the rough concentrate, and then the materials are mixed;

[0035] In step (4), the compressive strength of the obtained reduced-roasted iron oxide ore green pellets is 8.5N, and the number of drops is 4 times.

Embodiment 3

[0037] The difference between embodiment 3 and embodiment 1 is:

[0038] In step (1), the iron grade of the obtained iron ore coarse concentrate product is 43.4%;

[0039] In step (3), fine-grained tailings equivalent to 8% of the mass of the coarse concentrate and 1% coal powder are mixed into the rough concentrate, and then the materials are mixed;

[0040] In step (4), it was tested that the compressive strength of the obtained reduced-roasted iron oxide ore green pellets was 8.8N, and the number of drops was 3.9 times.

technical field

[0001] The invention belongs to the technical field of iron metallurgy, and relates to a method for producing iron oxide ore reduction roasting green pellets by utilizing iron beneficiation tailings. Background technique

[0002] With the rapid expansion of the scale of domestic iron and steel enterprises, the contradiction of insufficient iron ore resources has become increasingly serious. On the one hand, iron and steel enterprises expand imports and invest in foreign mines, and on the other hand, they speed up the development of domestic ores. Due to the high cost of imported ores, more and more enterprises choose the latter. Iron ore that is poorer and more difficult to select will also come into the eyes of developers, and there are a large number of iron oxide ores that are weakly magnetic. One of the important utilization ways of this part of iron ore is reduction roasting-magnetic separation.

[0003] Weak magnetic iron oxide ore refers to the sing...

Examples

Embodiment 1

[0026] A method for making iron oxide ore reducing and roasting green pellets by using iron beneficiation tailings, comprising the following process steps:

[0027] (1) Crush and grind the weakly magnetic iron oxide ore until the particle size is -200 mesh, accounting for 60-70%, through strong magnetic separation (selection parameters: magnetic field strength 0.8-1.2T, turntable speed 5 rpm, rinse water 20-25L / min) discard the qualified tailings with an iron grade below 13% in advance to obtain iron oxide ore rough concentrate products with an iron grade of 40.6%, and filter the obtained rough concentrate to a moisture content of 8- 13%;

[0028] (2) Classify the qualified tailings after the strong magnetic separation in step (1) through a cyclone to obtain a fine-grained tailings product with -400 mesh greater than 80%;

[0029] (3) Add fine-grained tailings equivalent to 2% of the mass of coarse concentrate and 3% coal powder into the rough concentrate, and then mix the ma...

Embodiment 2

[0032] The difference between embodiment 2 and embodiment 1 is:

[0033] In step (1), the iron grade of the obtained iron ore coarse concentrate product is 41.2%;

[0034] In step (3), fine-grained tailings equivalent to 5% of the mass of the coarse concentrate and 5% coal powder are mixed into the rough concentrate, and then the materials are mixed;

[0035] In step (4), the compressive strength of the obtained reduced-roasted iron oxide ore green pellets is 8.5N, and the number of drops is 4 times.

Embodiment 3

[0037] The difference between embodiment 3 and embodiment 1 is:

[0038] In step (1), the iron grade of the obtained iron ore coarse concentrate product is 43.4%;

[0039] In step (3), fine-grained tailings equivalent to 8% of the mass of the coarse concentrate and 1% coal powder are mixed into the rough concentrate, and then the materials are mixed;

[0040] In step (4), it was tested that the compressive strength of the obtained reduced-roasted iron oxide ore green pellets was 8.8N, and the number of drops was 3.9 times.