THE WEAR-RESISTANT PIPELINES with ALUMINOTHERMIC CORUNDUM COATING

THE WEAR-RESISTANT PIPELINES with ALUMINOTHERMIC CORUNDUM COATING

Energohimkomlect ltd.Chelyabinsk, Russia

Examples of the usage of hydraulic transport of materialsin various branches of industry:

Branch of industry Transported materialProduction of cement (wet process) Moistened raw materials (limestone, chalk, clay)Chemical industry Various pulpsCoal fired TPP Slag, fly ash, scrubber sludge, limestoneCoal mining, coal preparation Raw coal slurries, magnetite, tailingsMetallurgy Blast furnace slag, furnace scrubber slurry, drossProduction of phosphates Phosphate ore, tailingsPotassium fertilizers Potassium salts, kieserite, saltsRefuse incineration Slag, incombustible residueSand and gravel plants Sand, gravelSewage treatment Storm water, grit, sludge

Examples of the usage of pneumo transport of materialsin various branches of industry:

Branch of industry Transported material

Aluminium industry Calcined alumina, bauxite, electrode carbon, crushed bath

Food industry Corn, barley, soybeans, malt, cocoa beans, sunflower seeds, rice hulls

Production of cement Clinker dust, limestone, cement, fly ash, coal, furnace slag

Chemical industry Caustic lime, fertilizers, lime dust, chrome ore, plastic pellets with glass fibers

Coal fired TPP Coal, fly ash, slag, limestone

Coal mining, coal preparation Coal dust, mine waste

Foundry Foundry sand, dust collection

Glass plants Glass batch, cullet, quartz, kaoline, feldspar, nepheline

Metallurgy Sinter dust, limestone, alloy additives, coke, ores

Minerals industry Kiln feed, ore concentrates, coal, tailings, dust

Mineral and refractory fiber production Perlite, stone dust, refractory fibers, wastes, dust from sawing

Refuse incineration, vacuum refuse collection systems Domestic and industrial refuse

Sewage treatment Limestone, organic fertilizer, bio solids

Technical carbon products Technical carbon, dust, graphite

Hydraulic ash and slag removal systemwith dual disposal of ash and slag

Hydraulic ash and slag removal systemwith separated disposal of ash and slag

Pneumohydraulic ash and slag removal system

The main factors affecting the abrasive and corrosive wear of equipment and pipelines:

1. Abrasive properties of conveyed particles, hardness, sharpness and size.

2. Corrosion properties of the transported material.3. Velocity of the moving of pneumo- and hydromixtures.4. The materials of which equipment and pipelines are made.5. The quality of the installation.6. The position of the pipeline (the slope).7. The presence of bends of the pipeline and bending radius.

Measures to reduce the abrasion of pipelines:

1. Periodic rotation of the rectilinear pipes around their axis at 90 °.2. Transportation of hydro- or dust-air flow with velocities and

concentrations of solid material, not exceeding the optimum ones.

3. Shape optimization of curved sections of pipelines (reducing of bend radius).

4. Making of the sections of aerodynamic stabilization of flows at the entrance to the shaped sections of dust flues and the output of these, taking into account the zones of maximum wear.

5. Using of wear resistant elements of equipment and pipelines.

Wear-resistant elements of pipeline

Ceramic aluminothermic coatings

Stone casting

Alloy steels, rubberize steels, enameled steels

High-carbon steels

Steel 3, steel 20Incr

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Steel pipe with basalt insert(EUTIT s.r.o, Czech)

AlUMINOTHERMIC COATINGS

Reduction of iron oxides by aluminum (aluminothermy):

3Fe3O4 + 8Al → 4Al2O3 + 9Fe (1)-ΔH298

0 = 839 kJ/mole Al2O3, tad.comb. = 3194 °С

Fe2O3 + 2Al → Al2O3 + 2Fe (2)-ΔH298

0 = 856 kJ/mole Al2O3, tad.comb. = 3428 °С

The formation of aluminothermic coatingon a vertically mounting pipe by reactionary fusing method

1 – Igniter2 – Thermite mixture3 – Molten slag (Al2O3)4 – Molten reduced iron5 – Surfaced ceramic coat (Al2O3)

The formation of aluminothermic coatingon a bended pipe (elbow) by reactionary fusing method

1 – Igniter2 – Thermite mixture3 – Molten slag (Al2O3)4 – Molten reduced iron5 – Surfaced ceramic coat (Al2O3)

Pipes Ø273х10 mm, length 2 m

Three way pipe Ø108 mm

Test of thermite mixture in the pipe Ø108 mm, length 600 mm

Test of thermite mixture in the pipe Ø108 mm, length 600 mm

Test of thermite mixture in the pipe Ø108 mm, length 600 mm

Test of thermite mixture in the pipe Ø108 mm, length 600 mm

Test of thermite mixture in the pipe Ø108 mm, length 600 mm

Test of thermite mixture in the pipe Ø108 mm, length 600 mm

Test of thermite mixture in the pipe Ø108 mm, length 600 mm

Test of thermite mixture in the pipe Ø108 mm, length 600 mm

Test of thermite mixture in the pipe Ø108 mm, length 600 mm

Test of thermite mixture in the pipe Ø108 mm, length 600 mm

Test of thermite mixture in the pipe Ø108 mm, length 600 mm

The formation of aluminothermic coatingon a pipe Ø273х10 mm, length 2 m

The formation of aluminothermic coatingon a pipe Ø273х10 mm, length 2 m

The formation of aluminothermic coatingon a pipe Ø273х10 mm, length 2 m

The formation of aluminothermic coatingon a pipe Ø273х10 mm, length 2 m

The formation of aluminothermic coatingon a pipe Ø273х10 mm, length 2 m

The formation of aluminothermic coatingon a pipe Ø273х10 mm, length 2 m

The formation of aluminothermic coatingon a pipe Ø273х10 mm, length 2 m

The formation of aluminothermic coatingon a pipe Ø273х10 mm, length 2 m

The formation of aluminothermic coatingon a pipe Ø273х10 mm, length 2 m

The formation of aluminothermic coatingon a pipe Ø273х10 mm, length 2 m

The formation of aluminothermic coatingon a pipe Ø273х10 mm, length 2 m

The formation of aluminothermic coatingon a pipe Ø273х10 mm, length 2 m

The formation of aluminothermic coatingon a pipe Ø273х10 mm, length 2 m

The formation of aluminothermic coatingon a pipe Ø273х10 mm, length 2 m

The formation of aluminothermic coatingby centrifugal SHS-casting method

The structure of aluminothermic coatingproduced by centrifugal SHS-casting method

The cross-section of steel pipe with aluminothermic coating

a – the pipe wall;b – an intermediate metal layer;c – ceramic layer.

The microstructure of the ceramic layer

The comparative properties of pipelines materials

CharacteristicAluminothermic ceramic

coatingWear-resistant stone casting (cast basalt)

Gray cast iron СЧ 12-28

Thickness of coating, mm 3 – 4 20 -Density of coating, g/cm3 2,9 3,0 7,2Water uptake, % 0,09 0,13 не опр.Compression strength, MPa

300…340 250…500 500

Flexural strength, MPa 70…110 30…50 280Impact strength, kJ/m2 1,50 1,25 3,00Elastic modulus, MPa 102000 100630 120000Wear resistance, g/cm2 0,02 0,30 0,79Mohs hardness 8…9 7…8 not determ.Microhardness, GPa 15…18 5…9 not determ.Heat resistance, the number of thermo cycles from 800 °С to 20 °С in air

not less 10 1 not determ.

Heat resistance, the number of thermo cycles, quenching from 800 °С to 20 °С into water

not less 2 cracking not determ.

Acide resistance, 20% HCl, %

98 89 not determ.

Acide resistance, H2SO4

(96%), %99 97 not determ.

Primary characteristics of the aluminothermic coating

Wear resistance

Heat endurance (proven endurance up to 1200 °C)

Heat resistance (at least 2 thermal shocks from 800 °С into the water with 20 °С)

The thickness of the coating is adjusted from 2 to 8 mm

Resistance to electric welding

High acid- and corrosion resistance

JSC “Chelyabisk Zink Plant”Pneumatic transport of calcined Waelz oxide• Straight pipes Ø159х8 mm, length 2 m, steel 20• Elbow Ø159х8 mm, 90°

Tobolskneftehim ltd.Pneumatic transport of catalyst, temperature up to 650 °С• Cyclones Ø140-331х12 , height 556 mm, steel 12Х18Н10Т

JCS “Malyshev Ore Department”Jet mills for mica grinding• Acceleration pipes Ø67х8 mm, length 600 mm

Implemented products with aluminothermic coatings