BEIJING GUOHUA TECHNOLOGY GROUP · process using less equipment (without desliming screens,...

Simplified & High Efficient Coal Process Technology For Mongolian Coal

Jimmy YuVP, Ph.D, PEng.

Tangshan Guohua Technology Corporation

Beijing Guohua Technology Group

Tangshan, Heibei, China 063020

BEIJING GUOHUA TECHNOLOGY GROUP

OUTLINE

Characteristics of Mongolia Coal

Simplified & Highly Efficient HM Process Technology

Conclusions

Introduction

Advanced fine coal slurry treatment circuits

Advantages of the new HM Process Over Traditional Process

INTRODUCTION

Most of coals in North America are easy to wash.

Clean coal yield & recovery is usually low using conventional processing technologies to process difficulty-wash coalHigh efficient and simplified process technologies are needed to develop to recover more clean coal and to save capital & operating costs at the same time.

However, most of coals in China and some of Mongolia coals are difficult to wash or require high separation density.

Characteristics of Mongolian Coal

One Example of Mongolian Coking Coal Samples

Either 1) To produce clean coal ash content at 8%, separation density required is over 1.9 kg/L, or 2) Produce low ash clean coal at 5.5% with 1st stage separation density 1.45 and middling

at 23% ash with 2nd stage separation density 1.9 and pure rejectOr 3) Combine clean coal and middling as final clean coal at ash content of 8% and pure reject.

PROBLEMS WITH TRADITIONAL PROCESS FOR DIFFICULTY-WASH COALS

Circuit is complicated with a lot of equipment involved

A large amount of secondary coal fines generatedduring washing process

High Capital investment and high operating cost

Low separation efficiency at high separation density

Complicated and costly circuit for fine coal treatment


North America

Spiral

Cyclone Derrick

Deslime screen

Sizing screen

H.M. Drum

W.O. cyclone

Classifying cyclone

Slurry pumped outside plant

Spiral feed pump tank

Classifying cyclone feed pump tank

Classifying cyclone

Classifying cyclone

What Is Simplified & High Efficient HM Process ?1.1

Typical New Heavy Medium Flowsheet

SIMPLIFIED & HIGHLY EFFICIENT HM PROCESS SOLVES THE PROBLEMS

Raw coal

3-product H.M. cyclone

Middlings sieve bend

Clean coal sieve bend

Circulating water

Clean coal H.M. drain, rinse& classifying screen

Fine coal H.M. cycloneMiddlings H.M. draining & classifying

screen

Reject HM draining screen

Reject

Reject magnetic separator

Centrifuge Middling magnetic separator

Clean coal magnetic separator Centrifuge

Flow spilter

Flow spilter

Raw coal H.M. tank Middlings Clean coalTo clean fine

sieve bendTo 1st stage thickener

Rejects

Middlings Clean coal

Raw coal

3-product H.M. cyclone

Clean coal sieve bend

Circulating water

Clean coal H.M. D & R& classifying screen

Reject D&R

screenReject

Reject magnetic separator

Clean coal magnetic separator

Centrifuge

Flow spilter

Raw coal H.M. tank

Clean coal

clean fine sieve bend

Rejects

Clean coal

Clean coal

1st stage thickener

Fine coal H.M. tank

Reject D&R

screen

Typical Thermal Coal HM Process Circuit uisng Gravity-fed non-desliming 3-product cyclone

ADVANTAGES OF NEW HM PROCESS OVER TRADITIONAL PROCESS

1. The new HM process with non-desliming significantly simplifies HM process using less equipment (without desliming screens, hydro-cyclone, spirals, TBS and etc.) and smaller plant space required, which results in lower capital investment

2. Gravity-fed reduces secondary coal fines generation considerably

3. Lower operating cost due to simple process, less equipment & much higher separation efficiency than traditional processes

4. Using low single density HM suspension to achieve stable high separation density

5. Much higher clean coal yield due to higher separation efficiency compared to traditional HM process especially for high ash and difficulty-washing coal or when requiring high separation density


1. The new HM process with non-desliming significantly simplifies HM process using less equipment (without desliming screens, hydro-cyclone, spirals, TBS and etc.) and smaller plant space required, which results in lower capital investment


North America

Spiral

Cyclone Derrick

Deslime screen

Sizing screen

H.M. Drum

W.O. cyclone

Classifying cyclone

Slurry pumped outside plant

Spiral feed pump tank

Classifying cyclone feed pump tank

Classifying cyclone

Classifying cyclone


2. Gravity-fed reduces secondary coal fines generation considerably

Industrial plant tests indicate: The secondary slime generated during washing process

with gravity-fed H.M. cyclone is 5~7 percentage points (in total feed) less than that

produced during process with pressurized feeding cyclone. It is very important and

beneficial to the design of thermal coal plant.

Pump feed Gravity feed Difference

Slurry Volume (m3/h) 700 700

Solid Content (g/L) 135 102

Amt of -0.5 mm (t/h) 94.5 71.4 32.4%

Test at Linhuan Plant: Difference of Amount of -0.5 mm Fines between Gravity-fed & Pump-fed

※ Each cyclone feed rate: 302 t/h


3. Lower operating cost due to simpler process, less equipment, & much higher separation efficiency (higher centrifugal force and lower separation size limit) than traditional processes

• Higher centrifugal force: HM suspension feed pressure is double the traditional HM process (17 times of cyclone diameter instead of 8 times)

• Lower separation size limit: effectively separate coal particle size down to 0.25 mm in the 3-product cyclone and down to 0.1 mm in fine coal HM cyclone

0.5~0.25 mm 0.099kg/L

588~606 t/h,

0.1~0.074 mm 0.08 kg/L No ultrafine magnetite needed

588~606 t/h,

> 0.5 mm (I) 0.02-0.025 (II) 0.025-0.045

Coal Size Fraction Epm Value Throughput Capacity


3. Lower operating cost due to simpler process, less equipment, & much higher separation efficiency (higher centrifugal force and lower separation size limit) than traditional processes

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

Coal feed particle size (mm)

Ep Value

Spiral

TBS

GTC H.M. Cyclone

0.060.07

0.120.123

0.225

0.275

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2


Ep Value

Spiral

TBS

GTC H.M. Cyclone

0.060.07

0.120.123

0.225

0.275

The Performance (Ep Values) ofSpiral, TBS & HM Cyclone VS. Coal Size

Reference: “Performance of the Teetered Bed Separator at the Murray Energy Century Preparation Plant”- Paper published in Coalprep 2009 Kentucky


4. Using low single density HM suspension to achieve stable high separation density

Raw feed

Clean

Heavy medium

Middling

Reject

s.g./1.4

s.g. 1.8

E.g.,

Heavy medium

Vortex finder Apex


5. Much higher clean coal yield due to higher separation efficiency compared with traditional HM process especially for high ash and difficulty-washing coal requiring high separation density

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2


Ep Value

Spiral

TBS

GTC H.M. Cyclone

0.060.07

0.120.123

0.225

0.275

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2


Ep Value

Spiral

TBS

GTC H.M. Cyclone

0.060.07

0.120.123

0.225

0.275

Raw coal

HM

Clean coal Middlings

Reject

1st Stage HM 2nd Stage HM

1.851.45 D

ensi

ty

Den

sity

Time Time

1) Unstable separation density with traditional process

2) Higher separation efficiency for fine coal fraction

Magnetite Consumption★

< 1.0 kg/t at many normal circumstances in the plants designed by

TGTC using gravity-fed non-deslime 3-product H.M. Cyclone

process;

For example, 0.55 kg/t in Wenfeng plant

0.51kg/t in Tianwei plant

since the plants were operated.


ADVANCED FINE COAL SLURRY TREATMENT CIRCUIT

Clean Fine Circuit:(Coking coal)

2-Stage Flotations & 2-Stage Dewatering

Tailing�from�cleancoal�magnetic�separator

Filtrate�as�wash�water

Filter�press

Flotation�cells

Clean�fine�sieve�bend

Screen - bowl�centrifuge

The�buffer�tank/pump�for�flotation

Flotationcells

Flotation�concentrate�tank/pump

Filtrate

Tailing�from�cleancoal�magnetic�separator

Filtrate�as�wash�water

Filter�press

Flotation�cells

Clean�fine�sieve�bend

Screen - bowl�centrifuge

The�buffer�tank/pump�for�flotation

Flotationcells

Flotation�concentrate�tank/pump

Filtrate

Coarse fine circuit

Coarse fine circuit

Fine circuitFine circuit

Fine Tailings Circuit: 2-Stage Thickening & 2-Stage Dewatering

Coarse fine circuit

Coarse fine circuitFine circuitFine circuit

ADVANCED FINE COAL SLURRY TREATMENT CIRCUIT

OUTLINE

Conclusions

Majority of Chinese and some of Mongolia coals contain high ash,belong to difficulty-washing coals, or/and require high separationdensity during the process

The new HM process, using gravity-fed non-desliming 3-productcyclone, has been extensively used in more than 450 coal preparationplants in China (98 plants in Inner Mongolia) with completely close-circuit operation, will be suitable to Mongolia coal

Based on the large amount of industrial proven data, using the newdeveloped HM process will be expected to significantly increase cleancoal yield when used in Mongolia coal industry due to its much highseparation efficiency. Simultaneously, capital investment & operatingcosts can be considerably reduced by 20~40 %.

CONCLUSIONS

TANGSHAN GUOHUA TECHNOLOGY CO., LTD.

Mixed, non-deslimed gravity-fed 3-product heavy medium cyclone technology

Gravity-fed 3-product H. M. cyclone

DEVELOPMENT OF TECHNOLOGIES AND EQUIPMENTGravity-fed 3-product H.M. cyclone


Gravity-fed and 3-product cyclone toproduce clean coal, middlings and reject atone time

Without desliming & without sizing rawcoal feed

Using single low density H.M. to realizehigh density separation

Large capacity: the largest cyclone3GDMC1500/1000 has a capacity of 550-650t/h without desliming

The gravity-fed 3-product cyclonetechnology has been used in over 400 plants inChina.


Features & Advantages:

Country Model and I.D.mm

# of product

Feedingmanner

Feed sizemm

Requirement for raw coal

Capacityt/h

Epmkg/L

Adjustment of2nd stage

separation density

Australia DSM1300 2 pressure 110~1.5 Deslimed 550 0.02~0.03 －

Britain LARCODEMS1350 2 Gravity-fed 120~1.5 Deslimed 450 0.02~0.03 －

Russia ΓTY900/630 3 Pressure 50~0.5 Deslimed 200 Epm1=0.03~0.04 Epm2=0.05~0.08

Shut-down to replace apex

China 3GDMC1500/1100A 3 Gravity-fed 110~0Non-deslimedNon-classified 606 Epm1=0.02~0.03

Epm2=0.04~0.06 On-line to adjust

Comparison of major technical specifications of domestic

and oversea large diameter heavy medium cyclones



Performance of gravity-fed 3-product H. M. cyclone 2.1

Separation results using gravity-fed 3-product heavy medium cyclone

Plant Specifications of cyclone

Feed size mm

±0.1%

Ash,% Clean coal yield

%

Separation densitykg/L

Epkg/L

Raw Clean Coal Middlings Reject 1st stage 2nd stage 1st stage 2nd stage

Shanxi Wenfeng 1100/780 80-0 6.55 15.77 6.37 35.23 80.27 82.04 1.529 1.963 0.022 0.048

Anhui Linhuan 1200/850 95-0 14.30 36.03 9.79 37.79 85.17 61.79 1.540 1.860 0.020 0.040

Guizhou Laowuji 1300/920 80-0 38.26 34.22 9.54 24.47 76.99 56.65 1.430 1.688 0.025 0.045

Shanxi Jinyan 1400/1000 80-0 47.58 31.78 11.51 27.89 67.66 49.95 1.476 1.749 0.021 0.042

QipanjingInner

Mongolia1500/1100 100-0 47.06 46.92 10.19 25.39 71.37 25.31 1.415 1.670 0.022 0.024



Coal Size Fraction > 0.5 mm (I) 0.02 – 0.025 (II) 0.025 – 0.05

Ep Value

The low separation size limit of gravity-fed 3-product H.M. cyclone and fine coal H.M. cyclone2.2

The plant test data on 3GDMC1500/1100 H.M. cyclone at Qipangjing :



0.5~0.25 mm

Coal Size Fraction Epm Value Throughput Capacity

0.099kg/L 588~606 t/h,

The fine coal H.M. cyclone performance at the plant :

Coal Size Fraction Epm Value

0.1~0.074 mm 0.08 kg/L

There is no extra ultrafine

magnetite system needed

The Performance (Ep Values) of Spiral and TBS Versus Coal Particle Sizes

Reference: “Performance of the Teetered Bed Separator at the Murray Energy Century Preparation Plant”- Paper published in Coalprep 2009 Kentucky

DEVELOPMENT OF TECHNOLOGIES AND EQUIPMENT

Ep

Valu

es

Coal feed particle sizes (mm)

0.33

0.29

0.225

0.122

0.10 0.25 0.50

Coal slime slurry treatment technology

The “2+2” model of fine circuit process has been developed since 2006

The “2+2” model means:Fine clean coal circuit: 2-stage flotation and 2-stage dewateringFine tailings circuit: 2-stage thickening and 2-stage recovery

The purpose of “2+2” model slime circuit process:Recover all coal fines in plant and further reduce fine product H2O content

Realize closed water circuit in the plant with zero discharge of effluentSaving water with only 0.05-0.07 m3/t of water consumption in the plant

DEVELOPMENT OF TECHNOLOGIES AND EQUIPMENTFine Coal Circuit Process Technology

Fine Coal Slime Circuit Process Technology

To develop unique classified flotation process technology to handle low-

floatability and poor selectivity coal to reduce about 1% clean coal ash

content.

Addition of “coarse fine particles” into flotation froth to increase

capacity of de-watering equipments and reduce moisture content of

products;

Using two-stage de-watering, screen bowl centrifuge and filter press, to

reduce 5~10% of moisture content of clean fine coal.



Objectives:

Fine tailing process circuit flowsheet6.2

Objective:

① Maximizes the recovery of coarse fine reject, reduce its moisture contentand mix it with middlings;

② Realizes complete separation of solid and liquid for fine tailing slurry；

③ Addition of Ca++ and Mg++ ionic agglomerates as primary agentsand polypropylene type flocculant as a secondary agent to ensure completeclarifying of coal slurry and realize using clear water to wash coal.



BEIJING GUOHUA TECHNOLOGY GROUP · process using less equipment (without desliming screens,...

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