Pollution-free method for recycling iron-based grinding waste

Abstract

The invention provides a pollution-free reuse method for iron-based grinding waste, involving the technology of recycling economy, with special reference to the metallurgical industry, iron-based grinding waste green recycling technology. The present invention of the iron grinding waste recycling and reuse methods includes degreasing, heat treatment, sieving, matching, and obtains iron-based alloyed powders, which can be used in SHS lined steel pipe, powder metallurgy structural component, magnetic grinding, thermal spray. More than 95% iron-based alloyed powders can be recycled from wide source of iron-based grinding waste. The invention has the advantage of low cost, no secondary pollution and wide application.

Claims

1. A method of recycling an iron-based grinding waste, comprising: obtaining an iron-based grinding waste comprising iron, SiO.sub.2, and Al.sub.2O.sub.3; mixing a surfactant with the iron-based grinding waste and washing the mixture in water; heating the washed iron-based grinding waste at 200° C. to 800° C. to obtain a first iron-based alloyed powder; sorting the first iron-based alloyed powder according to powder particle sizes to obtain a plurality of iron-based alloyed powders; and mixing the plurality of iron-based alloyed powders to obtain a second iron-based alloyed powder; and compacting and sintering the second iron-based alloyed powder in a hydrogen atmosphere to produce a powder metallurgy product, wherein the second iron-based alloyed powder has 20-45 wt % of the powder particles in −240 to +400 mesh, 30-60 wt % of the powder particles in −160 to +240 mesh, 10-15 wt % of the powder particles in −80 to +160 mesh, and 5-10 wt % of the powder particles in −40 to +80 mesh.

2. The method of claim 1, wherein the surfactant is diocty sodium sulfosuccinate and a content of the surfactant is 1% to 3% by mass of the iron-based grinding waste.

3. The method of claim 1, wherein heating the washed iron-based grinding waste is performed at 200° C.

4. The method of claim 1, wherein the second iron-based alloyed powder comprises 70.2% or 81.6% of iron by weight.

5. The method of claim 1, wherein the method does not comprise milling.

6. The method of claim 1, further comprising recycling organics after the heating step.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) The FIGURE is a graph illustrating hysteresis loop and magnetization curve of the iron-based alloyed powders.

DETAILED DESCRIPTION

EXAMPLE 1

(2) Mix the iron-based grinding waste with the surface active agent Diocty Sodium Sulfosuccinate uniformly with their mass ratio being 100:1. Then pour water to them, stir, and wash. Put the washed waste in oven at 200° C. for 2 h, and we get the iron-based alloyed powders with TFe=81.6%.

EXAMPLE 2

(3) Mix the iron-based grinding waste with the surface active agent Diocty Sodium Sulfosuccinate uniformly with their mass ratio being 100:3. Then pour water to them, stir, and wash. Put the washed waste in oven at 800° C. for 0.5 h, and we get the iron-based alloyed powders with TFe=70.2%.

EXAMPLE 3

(4) Mix the iron-based grinding waste with the surface active agent Diocty Sodium Sulfosuccinate uniformly with their mass ratio being 100:1. Then pour water to them, stir, and wash. Put the washed waste in oven at 200° C. for 2 h, and we get the iron-based alloyed powders with TFe=81.6%. Sieve it to get the −40˜+400 iron-based alloyed powders. Mix the reducing agent aluminum powders with the sieved iron-based alloyed powders uniformly with the mass ratio 1:3, then put the mixture as the raw materials of the SHS lined steel pipe in a steel pipe with φ80 mm, 4 mm thick and 150 mm long. Fix the steel pipe to the tube machine and turn on it, light the mixture with tungsten filament. After the reaction, there is a ceramic coating with smooth surface and no flaw distributed in the inner surface of the steel pipe.

EXAMPLE 4

(5) Mix the iron-based grinding waste with the surface active agent Diocty Sodium Sulfosuccinate uniformly with their mass ratio being 100:3. Then pour water to them, stir, and wash. Put the washed waste in oven at 800° C. for 0.5 h, and we get the iron-based alloyed powders with TFe=70.2%. Sieve it to get the −40˜+400 iron-based alloyed powders. Mix the reducing agent aluminum powders with the sieved iron-based alloyed powders uniformly with the mass ratio 1:4, and put the mixture as the raw materials of the SHS lined steel pipe in a steel pipe with φ80 mm, 4 mm thick and 150 mm long. Fix the steel pipe to the tube machine and turn on it, light the mixture with tungsten filament. After the reaction, there is a ceramic coating with smooth surface and no flaw distributed in the inner surface of the steel pipe.

EXAMPLE 5

(6) Mix the iron-based grinding waste with the surface active agent Diocty Sodium Sulfosuccinate uniformly with their mass ratio being 100:1. Then pour water to them, stir, and wash. Put the washed waste in oven at 200° C. for 2 h, and we get the iron-based alloyed powders with TFe=81.6%. Sieve it to get the −200˜+300 iron-based alloyed powders. Mix the reducing agent aluminum powders with the sieved iron-based alloyed powders uniformly with the mass ratio 1:5, and put the mixture as the raw materials of the SHS lined steel pipe in a steel pipe with φ80 mm, 4 mm thick and 150 mm long. Fix the steel pipe to the tube machine and turn on it, light the materials with tungsten filament. After the reaction, there is a ceramic coating with smooth surface and no flaw distributed in the inner surface of the steel pipe.

EXAMPLE 6

(7) Mix the iron-based grinding waste with the surface active agent Diocty Sodium Sulfosuccinate uniformly with their mass ratio being 100:1. Then pour water to them, stir, and wash. Put the washed waste in oven at 200° C. for 2 h, and we get the iron-based alloyed powders with TFe=81.6%. Then interlot the iron-based alloyed powders with different particle size as the mass ratios below: 5% for −40˜+80 mesh iron-based alloyed powders, 10% for −80˜+160 mesh iron-based alloyed powders, 50% for −160˜+240 mesh iron-based alloyed powders, 35% for −240˜+400 mesh iron-based alloyed powders. After interlotted, compact the powders and sinter them in a hydrogen atmosphere to get powder metallurgy components.

EXAMPLE 7

(8) Mix the iron-based grinding waste with the surface active agent Diocty Sodium Sulfosuccinate uniformly with their mass ratio being 100:1. Then pour water to them, stir, and wash. Put the washed waste in oven at 200° C. for 2 h, and we get the iron-based alloyed powders with TFe=81.6%. Then interlot to these iron-based alloyed powders with different particle size as the mass ratios below: 5% for −40˜+80 mesh iron-based alloyed powders, 15% for −80˜+160 mesh iron-based alloyed powders, 40% for −160˜+240 mesh iron-based alloyed powders, 40% for −240˜+400 mesh iron-based alloyed powders. After interlotted, compact the powders and sinter them in a hydrogen atmosphere to get powder metallurgy components.

EXAMPLE 8

(9) Mix the iron-based grinding waste with the surface active agent Diocty Sodium Sulfosuccinate uniformly with their mass ratio being 100:3. Then pour water to them, stir, and wash. Put the washed waste in oven at 200° C. for 2 h, and we get the iron-based alloyed powders with TFe=81.6%. Then interlot to these iron-based alloyed powders with different particle size as the mass ratios below: 10% for −40˜+80 mesh iron-based alloyed powders, 10% for −80˜+160 mesh iron-based alloyed powders, 60% for −160˜+240 mesh iron-based alloyed powders, 20% for −240˜+400 mesh iron-based alloyed powders. After interlotted, compact the powders and sinter them in a hydrogen atmosphere to get powder metallurgy components.

EXAMPLE 9

(10) Mix the iron-based grinding waste with the surface active agent Diocty Sodium Sulfosuccinate uniformly with their mass ratio being 100:3. Then pour water to them, stir, and wash. Put the washed waste in oven at 200° C. for 2 h, and we get the iron-based alloyed powders with TFe=81.6%. Then interlot to these iron-based alloyed powders with different particle size as the mass ratios below: 10% for −40˜+80 mesh iron-based alloyed powders, 15% for −80˜+160 mesh iron-based alloyed powders, 30% for −160˜+240 mesh iron-based alloyed powders, 45% for −240˜+400 mesh iron-based alloyed powders. After interlotted, compact the powders and sinter them in a hydrogen atmosphere to get powder metallurgy components.

EXAMPLE 10

(11) Mix the iron-based grinding waste and the surface active agent Diocty Sodium Sulfosuccinate uniformly with their mass ratio being 50:1. Then pour water to them, stir, and wash. Put the washed waste in oven at 200° C. for 2 h, and we get the iron-based alloyed powders with TFe=81.6%. Because the iron-based alloyed powders has a good magnetic property, as showed in the FIGURE, it is suit for manufacturing magnetic abrasive. Mix the sieved iron-based alloyed powders (+140 mesh) with abrasive powders Al.sub.2O.sub.3 (+400 mesh) with the mass ratio 4:1 in anhydrous ethanol for 2 h. Dry the mixed powders and then put epoxy resin as the caking agent and polyamide resin as the curing agent into it. The mass of epoxy resin to Al.sub.2O.sub.3 is 1/3, and the mass of polyamide resin to the epoxy resin is 1/3. Mix all of them uniformly, compact them to bulks, solidify for 24 h in room temperature and smash them into magnetic abrasive powders.

EXAMPLE 11

(12) Mix the iron-based grinding waste and the surface active agent Diocty Sodium Sulfosuccinate uniformly with their mass ratio being 50:1. Then pour water to them, stir, and wash. Put the washed waste in oven at 200° C. for 2 h, and we get the iron-based alloyed powders with TFe=81.6%. Because the iron-based alloyed powders has a good magnetic property, as showed in the FIGURE, it is suit for manufacturing magnetic abrasive. Mix the sieved iron-based alloyed powders (+140 mesh) with abrasive powders SiC (+400 mesh) with the mass ratio 5:1 in anhydrous ethanol for 2 h. Dry the mixed powders and then put epoxy resin as the caking agent and polyamide resin as the curing agent into it. The mass of epoxy resin to SiC is 1/3, and the mass of polyamide resin to the epoxy resin is 1/3. Mix all of them uniformly, compact them to bulks, solidify for 24 h in room temperature and smash them into magnetic abrasive powders.

EXAMPLE 12

(13) Mix the iron-based grinding waste and the surface active agent Diocty Sodium Sulfosuccinate uniformly with their mass ratio being 50:1. Then pour water to them, stir, and wash. Put the washed waste in oven at 200° C. for 2 h, and we get the iron-based alloyed powders with TFe=81.6%. Because the iron-based alloyed powders has a good magnetic property, as showed in the FIGURE, it is suit for manufacturing magnetic abrasive. Mix the sieved iron-based alloyed powders (+140 mesh) with abrasive powders SiC (+400 mesh) and Al.sub.2O.sub.3 (+400 mesh) with the mass ratio 20:2:1 in anhydrous ethanol for 2 h. Dry the mixed powders and then put epoxy resin as the caking agent and polyamide resin as the curing agent into it. The mass of epoxy resin to the sum of the iron-based alloyed powders's and Al.sub.2O.sub.3 is 1/3, and the mass of polyamide resin to the epoxy resin is 1/3. Mix all of them uniformly, compact them to bulks, solidify for 24 h in room temperature and smash them into magnetic abrasive powders.

EXAMPLE 13

(14) Mix the iron-based grinding waste with the surface active agent Diocty Sodium Sulfosuccinate uniformly with their mass ratio being 100:1. Then pour water to them, stir, and wash. Put the washed waste in oven at 200° C. for 2 h, and we get the iron-based alloyed powders with TFe=81.6%. Sieve the iron-based alloyed powders to get −200˜+300 mesh powders. Mix the sieved powders with Ni.sub.60 powders with mass ratio 4:1. The mixed powders are the spraying materials for thermal spraying coating. Cut the No. 45 steel (Chinese standard) into 30 mm×15 mm×4 mm pieces. Remove the oxidations of the steel and clean the surface of the steel. Spray the mixed powders on the cleaned steel by HVOF to get good spraying coating.

EXAMPLE 14

(15) Mix the iron-based grinding waste with the surface active agent Diocty Sodium Sulfosuccinate uniformly with their mass ratio being 100:1. Then pour water to them, stir, and wash. Put the washed waste in oven at 200° C. for 2 h, and we get the iron-based alloyed powders with TFe=81.6%. Sieve the iron-based alloyed powders to get −200˜+300 mesh powders. Mix the sieved powders with Ni.sub.60 powders with mass ratio 5:1. The mixed powders are the spraying materials for thermal spraying coating. Cut the No. 45 steel (Chinese standard) into 30 mm×15 mm×4 mm pieces. Remove the oxidations of the steel and clean the surface of the steel. Spray the mixed powders on the cleaned steel by HVOF to get good spraying coating.

EXAMPLE 15

(16) Mix the iron-based grinding waste with the surface active agent Diocty Sodium Sulfosuccinate uniformly with their mass ratio being 100:1. Then pour water to them, stir, and wash. Put the washed waste in oven at 200° C. for 2 h, and we get the iron-based alloyed powders with TFe=81.6%. Sieve the iron-based alloyed powders to get −200˜+300 mesh powders. Mix the sieved powders with Ni.sub.60 powders with mass ratio 6:1. The mixed powders are the spraying materials for thermal spraying coating. Cut the No. 45 steel (Chinese standard) into 30 mm×15 mm×4 mm pieces. Remove the oxidations of the steel and clean the surface of the steel. Spray the mixed powders on the cleaned steel by HVOF to get good spraying coating.