1500t/d
1.、Production scale, production method and cement types
1.1 Production method
一3.5×54m五
The production method is dry process. A rotary kiln(3.5×54m)
production line with five-stage cyclone pre-heater and
decomposition furnace will be adopted.
1.2Production scale and capacity
1500500000
The production capacity is 1500t/d for clinker, while 500,000t/a
for Portland cement when mixed with gypsum.
1.3 Cement types
GB175-1999,32.5MP、42.5MP
The technology and equipment adopted can produce 32.5MP and 42.5MP
types of cement in accordance with Chinese Standard GB175-1999.
They can be adjusted according to market demand.
2.
2.1.Raw materials properties chemical composition
Name | L.O.I | SiO2 | Al2O3 | Fe2O3 | CaO | Mgo | K2O | Na2O | SO3 | Cl- | Water content | Density t/m3 |
Limestone | 39.27 | 7.17 | 2.93 | 1.25 | 46.94 | 1.03 | 0.13 | 0.23 | | 0.009 | 0.45 | |
Shale | 21.89 | 36.14 | 10.39 | 3.27 | 22.03 | 0.8 | 0.99 | 0.33 | | 0.015 | 0.46 | |
Silica | 0.10 | 95.5 | 1.00 | 0.20 | 0.90 | 0.50 | | | | | | |
Gypsum | | 1.40 | 0.60 | 0.20 | 30.52 | 0.05 | 0.10 | 0.10 | 47.10 | | 18.70 | |
iron | 11.5 | 30.56 | 22.12 | 26.91 | 1.12 | | | | | | | |
2.2Fuel
The technical property of mazut：Min. value is ≥9000
kcal/kg(37620kJ/kg)
The S content of mazut：
2.5 %.
2.3
一3.5×54m五62.5t/h850Kcal/kg （3552.0KJ/kg）
：
：850Kcal/kg.cl ：960kg/t.cl
KH=0.89±0.02
SM=2.6±0.1
IM=1.5±0.1
：
According to raw material and fuel conditions, the following
materials will be used for material blending: limestone, Silica,
and iron powder.
Proportional ratio of raw material（%） |
Limestone | clay | Sand | iron |
89.00 | 0 | 9.45 | 4.2 |
、
| LOSS | SiO2 | Al2O3 | Fe2O3 | CaO | MgO | K2O+N2O | SO3 | Cl- |
| 35.440 | 14.159 | 3.505 | 2.056 | 41.885 | 0.950 | 0.018 | 0.033 | 0.049 |
| | 21.311 | 5.225 | 3.196 | 63.041 | 1.430 | | | |
C3S | C2S | C3A | C4AF |
53.42 | 20.79 | 8.62 | 10.32 |
：KH=0.886 SM=2.53 IM=1.64
：1.556/
62.5082%1.620/840Kcal/kg.cl（3511.0KJ/kg）9000 kcal/kg(37620kJ/kg)一：
3. Main technical characteristics
3.1BS930
This production line adopts advanced technology and equipment in
1990s to raise technical level and to ensure design indexes. New
five-stage cyclone pre-heater system, high efficiency air girder
grate cooler, multi-passage pulverized coal burner, Davison heat
temperature fan, Luqi BS930 electrical dust collector, as well as
chain-board elevator, chain conveyor adopted in this production
line can ensure that the technology is advanced compared to other
production lines with the same scale.
3.2 、
If it has not bad influences on completenesscontinuity and
reliability, process procedures will be simplified to enhance
production management, reduce troubles and lower investment.
3.3 Simplifying houses for equipment to decrease building area
Top of silos are without covers, heat temperature fan and dust
collectors are open arranged and glass fiber rainproof covers
instead of roofs will be set for belt conveyor passages. There will
be no building for bucket elevator.
、
If it has not bad influences on normal production, by properly
reducing storage periods for all raw materials, semi-product and
finished product and adopting shed to store those materials and
products, civil engineering costs will be greatly reduced.
Frame for pre-heater at kiln inlet will adopt steel structure to
save investment, accelerate erection speed and beautify
building.
3.4 、
Measures have been taken to save energy and reduce consumption.
using chain-board elevator and air slides, reliability of the
system is enhanced and conveying energy consumption is decreased.
3.5
All necessary parts will adopt measuring equipment to guarantee
scientific management. For example, there are measuring equipment
at those parts such as raw meal blending, raw materials entering
into plant, raw meal feeding to kiln, pulverized coal feeding to
kiln, clinker outgoing kiln and clinker outgoing silos.
3.6
Effective measures have been taken to guarantee strict environment
protection standards. Different efficient dust collectors are set
at all dust producing points according to different characteristics
of waste gas.
4.Technical plan
4.1 Production process
4.1.1 、Production scale, production method and product plan
一15003.5×54m五
A new dry process production line with capacity of 1500t clinker
per day will be built. A rotary kiln(3.5×54m) will be used as
burning equipment. Five-stage cyclone pre-heater and
decomposition furnace will be adopted at kiln inlet.
4.1.2 Selection of main equipment and production facilities
4.1.2.1 Limestone crushing
Single-stage hammer crusher is used for limestone crushing. This
type of crusher is suitable in crushing medium strength ore such as
limestone, marlite, slag, gypsum and coal. It can crush big ore to
required size. Moreover, it can crush ore which has moisture and
earth in it because it adopts discharging grates in the same
direction. It has special iron feeding protection device, which can
rebound the uncrushed metals to the feeder, so the operator can
stop it if he hears peculiar sound to deal with this
matter.
TKPC16.18800mm250t/h25.51％
Limestone crushing will adopt TKPC16.18 single-stage hammer crusher
adopted. Feeding size is 800mm, production capacity is 380t/h
and annual usage rate is25.51％.
4.1.2.2 Raw meal grinding
1500t/dHRM2800m
For 1500t/d cement production line, available raw mill system is
HRM2800m mill system.
4.1.2.3 Raw meal homogenizing and storage
15×50mMF6500t2.86d
15×50mMF silo both can homogenize and store raw meal will be
adopted. Its capacity is 6500t and storage period is 2.86days.
4.1.2.3 Clinkering system
一五CDC、3.5×54m三1500t/d840Kcal/kg （3511.0KJ/kg）90%
A five-stage cyclone pre-heater system with CDC, 3.5×54m rotary
kiln and new air girder grate cooler, etc will be adopted for
clinker preparation. The capacity is 1700t clinker per day.
Clinkering heat consumption is 840Kcal/kg （3511.0KJ/kg）.
Decomposition degree of CaCO3 is larger than 90%. Extra heat of
waste gas is used for drying raw materials and raw coal.
、三61.8m262.5t/h＋65℃
The new type air girder grate cooler manufactured in China with
imported technology will be adopted for clinker cooling. Effective
area of grate bed is 61.8m2. Output is 62.50t/h. Outgoing
temperature of clinker is 65℃ higher than ambient temperature.
4.1.2.4Cement grinding
3.5×13mN-1500O-SEPA50t/h
Two3.5×13m model tube cement mills equipped with N-1500 model
O-SEPA air separator will be adopted for cement grinding. Its
capacity is 50t/h per set
4.1.3List of main equipment
No | Name of item | 、 Name, specification and performance | (t/h.) Capacity (t/h per set) | Quantity (Set) | (%) Annual running percentage rate | Remarks |
1 | Limestone crushing | Heavy type apron feeder ：B1250×11500mm Specification: B1250×11500mm ：800mm Feeding size: 800mm ：30kW Power: 30kW | 200～350 | 1 | 25.51 | |
Single-stage hammer crusher ：TKPC16.18 Model: TKPC16.18 ：800mm Feedingsize: 800mm ：≤25mm Outgoing size25mm ：355kW Power: 355kW | 250 | 1 | 25.51 |
2 | Limestone pre-homogenizing | Stacker-Reclaimer : 24m Distance between rails: 24m : 142kW Total installed power: 142kW Stacker : Stacking method: continuous : >400 Stacking layers: >400 Reclaimer : Reclaiming method: section reclaiming | : Stacking capacity: 600t/h : Reclaiming capacity: 250t/h | 1 | | |
3 | Raw meal grinding | mill ：HRM2800mm Specification: HRM2800mm ：≤40mm Feeding size40mm ：0.080mm12% Fineness of finished product: 12% (remainder above 0.080mm hole screen) ：≤6% Feeding moisture6% ：≤0.5% Outgoing moisture0.5% ：1250 kW Power: 1250kW | 130 | 1 | 60.90 | |
4 | 、 Treatment of waste gas of kiln inlet and mill | Humidity tower ：7.5×26m Specification: 7.5×26m : 400000m3/h Air capacity: 400000m3/h : 340℃ Feeding air temperature: 340℃ : 150-220℃ Outgoing air temperature: 150-220℃ | | 1 | 82.19 | |
High temperature fan 400000m3/h Flow: 400000m3/h 7500Pa Total pressure: 7500Pa ：340℃（450℃） Operation temperature: 340℃ (instant temperature 450℃) 1450r/min Rotary speed: 1450r/min : 1250kW Power: 1250kW | | 1 | 82.19 | |
2350DIBB24 :300000m3/h 7500 Pa c.BS930： :400000m3/h 80g/Nm2 50mg | | 1 | 82.19 | |
Waste gas fan at kiln inlet 420000m3/h Flow: 420000m3/h 1500Pa Total pressure: 1500Pa ：150℃ Operation temperature: 150℃ :355kW Power: 355kW | | 1 | 82.19 | |
5 | Kiln inlet | 五 Five-stage cyclone pre-heater and decomposition furnace system C1：2-4300mm C2：1-5600mm C3：1-5600mm C4：1-5900mm C5：1-5900mm ：6300mm decomposition furnace: 6300mm | 62.50 | 1 | 82.19 | |
6 | Kiln middle | Rotary kiln ：3.5×54m Specification: 4×60m 4% Inclination: 4% 0.4～3.96r/min Rotary speed: 0.4～3.96r/min : 220kW() Power: 220kW (DC speed adjusting) | 62.50 | 1 | 82.19 | |
7 | Kiln head clinker cooling | Air girder grate cooler ：LBTF1700 Model: LBTF1700 | 62.50 | 1 | 82.19 | |
8 | Cement grinding | Tube mill ：3.5×13m Specification: 3.5×13m : 320m2/kg Fineness of finished product: 320m2/kg : 2000kW Main motor power: 2000kW | 50 | 2 | 58.59 | |
Air separator ：O-Sepa1500 Model: O-Sepa2000 ：1500m3/min Air capacity: 1500m3/min | | 2 | 58.59 |
9 | Cement packing | 八 Eight-spout rotary packer ：±0.25kg/ Accuracy0.25kg per bag | 90 | 2 | 34.18 | |
4.1.4 Process procedures
4.1.4.1 Limestone crushing and pre-homogenizing
：TKPC16.18250/（≤25mm）
Limestone crushing workshop is set inside the plant, which adopting
single-stage crushing system. Limestone exploited in mining area
will be transported into plant by trucks and unloaded into hopper
in the limestone crushing workshop, and then fed onto TKPC16.18
hammer crusher by speed-governable heavy apron feeder. Rated
capacity of crusher is 250t/h. Crushed limestone (size:≤25mm) will
be fed onto the limestone pre-homogenizing stockyard by belt
conveyor. Then the limestone will be fed onto material blending bin
by belt conveyor.
一
To avoid dust pollution, an impulse bag filter will be used to
collect dust from crusher and discharging points of belt conveyor.
Purified air will be drained to the atmosphere.
4.1.4.2Crushing of slag, gypsum; Conveying of iron powder and
admixture
、
clay and gypsum will be transported into plant by trucks and
unloaded into different bins in the crushing station, and then fed
onto crusher by speed-governable apron feeder. Crushed materials
will be fed onto auxiliary materials stockyard by belt conveyor.
、
Iron powder and admixture will be fed onto auxiliary materials
stockyard by belt conveyor.
4.1.4.3 Raw material blending
一8×14m360t150t
Four bins will be set for material blending: one for limestone
(8×14m), one for clay(capacity: 360t)、sand (capacity: 360t) and one
for iron powder (capacity: 150t). Speed-governable chain-board
conveyors and electric belt balances will be used at the bottom of
material blending bins. Materials with required proportion will be
fed onto the raw mill by belt conveyor.
Raw meal quality control system consists of fluorescent light
analyzer and computer. It can automatically analyze raw meal
composition and automatically adjust rotary speed of chain-board
conveyors and electric belt balance according to analysis result
and target value, so that discharging amount of each kind of
material can be controlled.
4.1.4.4Raw meal grinding and treatment of waste gas
HRM2800、：0.08≤12%≤40mm≤6 %0.5%130≤350℃60.9%
Proportioned raw material will be fed onto the raw mill by belt
conveyor. The mill is middle-discharging drying mill which can dry
material and grind material. Its capacity is 150t/h. Drying heat is
from waste hot gas drained by high temperature fan at kiln inlet.
Gas temperature is 300℃. Drying heat is from waste hot gas drained
by high temperature fan at kiln inlet.
4.1.4.5、Treatment of waste gas of kiln and mill
一、
Waste gas from the pre-heater will be drained by high temperature
fan. Some of it will be sent to raw material grinding section as
drying heat. The other part will be adjusted by humidification
tower, then mix with waste gas drained from raw mill and purified
by bag filter, after that, it will be drained to the atmosphere by
fan.
When the raw mill is stops, all the waste gas from the pre-heater
will be sent to humidity tower. Dust collected by waste gas
treatment system will be fed to raw meal homogenizing silo or raw
meal weighing bin by chain conveyor and elevator. When working of
humidity tower is not normal and collected kiln dust has much
moisture, screw conveyor under humidity tower will reverse and
drain out wet kiln dust.
Manual car will move away the dust.
、、
Waste gas treatment system, raw mill and pre-heater frame are
rectangular arranged. Steel chimney is attached to pre-heater
frame. The arrangement is compact and earth saving. Moreover, waste
gas pipe is short, so investment can be saved.
4.1.4.6Raw meal homogenizing
一650015×50m（MF）、(MF)
A MF raw meal homogenizing silo (size:15×50m, storage capacity:
6500t ) is set. Qualified raw meal from raw mill will be sent to
top of raw meal homogenizing silo by bucket elevator and discharged
by silo top distributor. At the bottom of silo, raw meal will be
loosened by aeration system and then discharged to mixing bin under
silo. Raw meal will be further loosened and homogenized in the
mixing bin. Qualified raw meal will be fed to raw meal weighing bin
at the top of silo by air slide and bucket elevator. Weighed raw
meal will be fed to pre-heater by air slide and bucket elevator.
High pressure air for homogenizing is supplied by Roots blower
under homogenizing silo.
4.1.4.7Kiln inlet pre-decomposition and clinker burning
system
3.5×54m五CDC850Kcal/kg.cl（3552.0KJ/kg）1500
A rotary kiln (3.5×54m), low-pressure-loss five-stage cyclone
pre-heater and CDC decomposition furnace are adopted for
clinkering. Clinker capacity is 1500t/d, clinker heat consumption:
840Kcal/kg.cl（3511.0KJ/kg）. Coal usage ratio of kiln and
decomposition furnace is 40:60. Apparent decomposition rate of raw
meal feeding to kiln is about 90～95%.
三
Weighed raw meal will be fed to pre-heater. After heating, it will
be discomposed in decomposition furnace and then fed to kiln. Third
air for decomposition furnace is from kiln hood.
To avoid jam, expansion bin and automatic-control blowing system
and necessary compressed air devices will be adopted to guarantee
normal running of pre-heater.
+65℃、
Hot clinker feeding to great cooler will be cooled rapidly by cold
air from blower under grate board. Outgoing clinker from grate
cooler is 65℃ higher than ambient temperature. Then clinker will be
fed to clinker silo by bucket-chain conveyor.
Hot waste gas from grate cooler is divided into four parts: part of
it is sent to kiln as secondary air, part of it is sent to
decomposition furnace as burning air by tertiary duct, and the rest
is drained to the atmosphere after purified by electric dust
collector at kiln head. Dust collected by electric dust collector
will fed to bucket-chain conveyor by chain conveyor.
4.1.4.8Clinker storage
18×36m2600017
This section will adopt two silos with the size of 18×36m. Total
capacity is 26000t and storage period is 17days. Lateral clinker
bulking systems is set at the side of silos.
Clinker will be fed to cement mill by belt conveyor after
discharged by weighing machines at the bottom of silos.
4.2.5.9Cement blending and grinding
一
A gypsum bin is adopted. Computerized balance under the gypsum bin
will be used for material blending. The clinker and gypsum will be
fed to cement mill by belt conveyor after proportioned according to
cement modulus requirements.
3.5×13mN-1500O-SEPA50t/hO-SEPA
Two3.5×13m model tube cement mills equipped with N-1500 model
O-SEPA air separator will be adopted for cement grinding. Its
capacity is 50t/h per set. Cement discharged from cement mill will
be fed to O-SEPA air separator by bucket elevator and air slide.
Coarse powder will return to mill for regrinding. Finished product
will be sent to impulse bag filter. After collected by the bag
filter, it will be fed to cement silo by air slide and bucket
elevator.
4.1.4.10Cement storage
415×41m28000t15
Four silos (size:15×41m; total storage capacity: 28,000t, storage
period: 15days) equipped with depressurizing cones will be used for
cement storage. Air used for homogenizing is supplied by Roots
blowers under cement silos.
4.2.5.11Cement packing and finished product storehouse
二八100t/h
Two 8-spout packers will be used for cement packing. Packing
capacity is 100t/h per set.
八24×70m
Cement will be fed to vibrating screen by bucket elevator. Then
cement will be fed to constant pressure bin. After that, it will be
packed by eight-spout packer and transported to finished product
storehouse by belt conveyor.
Weight of bagged cement is weighed and adjusted by electric
balance.
Good dust collecting system is set for cement packing to guarantee
dust emission standard.
4.1.4.12 Central lab
A central lab is set in the plant to carry out normal chemical and
physical tests of raw materials, fuel, semi-products and finished
product, guarantee product quality in each section and adjust,
manage, monitor quality of cement product.
4.1.4.13 Process flow sheet
Refer to related drawing.
4.1.5 Weighing facilities
、
Measuring facilities and special measuring personnel are arranged
at all necessary parts in the production line to guarantee good
quality of product and to control production conditions.
List of weighing equipment
No. | Material | Position | Name of equipment | Qty. | Remark |
1 | 、 Raw materials and fuel | Entrance gate of the plant | Platform scale | 1 | |
2 | Limestone to be fed to raw mill | Under material blending bin | Speed-governable balance | 1 | |
3 | sand to be fed to raw mill | Under material blending bin | Speed-governable balance | 1 | |
4 | Iron powder to be fed to raw mill | Under material blending bin | Speed-governable balance | 1 | |
5 | Raw meal to be fed to kiln | Discharging point of weighing bin at kiln inlet | Speed-governable balance | 1 | |
6 | Clinker to be fed to cement mill | Under clinker silo | Speed-governable balance | 4 | |
7 | Gypsum to be fed to cement mill | Discharging point of feeding bin of mill | Speed-governable balance | 2 | |
8 | Admixture to be fed to cement mill | Discharging point of feeding bin of mill | Speed-governable balance | 2 | |
9 | Bagged cement | Packer | Electric balance | 2 | |
4.1.6 Maintenance facilities
（1
The plant can buy or rent a crane to repair open-arranged
equipment. In this way, investment on equipment, electricity and
civil engineering can be saved.
（2）、
For equipment which can not be open-arranged but is rarely used
(such as crusher and fan), maintenance lifting hook is set on
ceiling of the workshop.
（3
For equipment which is frequently used, electric hoist is set. For
example, electric hoists are used to lift refractory bricks at kiln
inlet and kiln head and to lift steel balls at raw meal grinding
workshop and cement grinding workshop.
4.2 Electric and automation
4.2.1 Electric
4.2.1.1 Power source
10 kV
Power is mainly supplied by public power supply net. Voltage is 10
KV.
4.2.1.2 Power voltage
10kV
Distribution voltage:10kV
0.4kV
Low voltage: 0.4kV
4.2.1.3 Powder demand
14500kW
4.2.2 Processing automation
4.3.2.1 Design principle
PLCPLC、
In order to reach to modern cement process requirements, guarantee
reliable running of process equipment, stabilize process
parameters, improve quality of product, increase running rate of
production line and save investment, advanced, reliable PLC
computerized control system will be used to realize centralized
monitoring and separate controlling of main production line.
In this way, reliability of electric control equipment is enhanced,
maintenance is easier and automatic control is realized. For cement
packing workshop, PLC field control station and field operation
station will be adopted. Signal will send to central control room
by high-speed communication net and then send to managing computer,
so that management personnel can know working conditions at any
time, thus management modernization can be realized.
4.3 Water supply and drainage
4.3.1
Design principle: saving water and earth, full use of water
resource and saving investment
4.3.2 Water amount
（1） 9654m3/d
： 8665m3/d
787m3/d(:414m3/d)
202m3/d
Production water of the whole plant: 9654m3/d
Including: Circulation water: 8665m3/d
Production consumption water: 787m3/d (reuse: 414m3/d)
&nbs,
p;Auxiliary production water: 202m3/d
（2）
8419m3/d
Returned circulation water:
8419m3/d
（3） 246m3/d
Supplement circulation water:
246m3/d
（4）
97.1%
Usage rate of circulation
water: 97.1%
（5）
180m3/d
Supplement fire-fighting
water: 180m3/d
（6）
80m3/d
Living water in the plant:
80m3/d
4.3.3 pressure of supplied water
Water pressure
：0.25～0.35MPa3.3MPa：0.1MPa
Pressure of production water: 0.25～0.35MPa at inlets of workshop
pipes, 3.3MPa at inlet of backflow spout of humidity tower.
Pressure of living water: according to water usage points. Pressure
of fire-fighting water: at outlets of outdoors fire
hydrants≥0.1MPa; For indoors fire hydrants: comply with water
pressure requirement of most disadvantageous points.
4.3.4 Water supply system
（1）Water supply system for production and circulation
GBNL3-350Q＝350.0m3/hN＝11kW2G250WFB-FDQ=260.0m3/hH=55.0mN=90kW三一)、
In order to save water, cooling water for production equipment in
each workshop will adopt close backflow and spare pressure sent to
tower circulation cooling system. A group of hot water pump and hot
water pool can be saved. Circulation water usage factor is high and
equipment, constructions, energy, earth and investment can be
decreased.
Water cooled by a GBNL3-350 model cooling tower (Q＝350.0m3/hN＝11kW)
will naturally flow to circulation water pool and will be
pressurized by circulation pumps (2G250WFB-FD model,
Q=260.0m3/hH=55.0mN=90kW, two are using and one is backup) and then
sent to cooling water usage points in the plant. Water loss in
circulation is supplemented by production and living piping net.
（2）、Water supply system for fire fighting and living
2G80WFB-CQ=45m3/hH=57mN=22kWV=500m3）
This system will supply living water, fire fighting water,
auxiliary production water, flushing water for grate cooler and
part of flushing water for humidity tower. There are two living
pumps, one is using and one is backup. The pump has 2G80WFB-C
model, capacity of 45m3/h, height of 57m and power of 22kW. Water
in living pool will be pressurized by living pump and then sent to
living water usage points in the plant. A pool (V=500m3) is set at
high position to adjust water amount and to store fire fighting
water.
、（DG25-50×9Q=25m3/hH=450mN=75kWD12-50×3Q=9m3/hH=165mN=15kW
Pressure pumps are adopted for water supply of humidity tower and
grate cooler. There are two pressure pumps for humidity tower, one
is using and one is backup. The pump has DG25-50×9 model, capacity
of 25m3/h, height of 450m and power of 75kW. There are two pressure
pumps for grate cooler, one is using and one is backup. The pump
has D12-50×3 model, capacity of 9m3/h, height of 165m and power of
15kW.
4.4 Building and structure
4.4.1 Building
4.5.1.1 Design principle
、、,
Areas, positions and spans should be decided according to general
layout, process flow and equip, , ment. The design chooses
security, economic and reasona, ble building plan should be chosen.
4.4.2 Structure
4.4.2.1 Design principle
、、
Reasonable, safe, economica, l an, d practical structure plan and
structure types s, houl, , d be chosen to comply with process, ,
requirements and usage requirements.
4.4.2.2 Structure design
（1）Selection of structure
一一
Cement plant has the following characteristics: complex process,
many machines, big load, many holes, hoppers and bins and irregular
forms. In order to comply with equipment arrangement requirements,
size of pillar net is usually big. Main workshops usually use
site-casting reinforced concrete structure and minor buildings and
auxiliary workshops can use step structure.
Multi-layer workshop such as kiln head, grinding, crushing,
pulverized coal preparation and cement packing workshops: adopting
site-casting reinforced concrete frame; foundation will use
reinforced concrete separate foundation or pile foundation.
：
Frame of pre-heater: the part under platform of smoke chamber will
use site-casting reinforced concrete frame while the upper part use
steel structure. Chimney at kiln inlet will use thin-wall steel
structure with kiln inlet frame as support. Foundation of
pre-heater frame will use reinforced concrete elasticity foundation
beam or pile foundation.
Pre-homogenizing stockyard for auxiliary materials: adopting
reinforced concrete pillar; room lid will use net structure; roof
and wall will use profiling steel plate; foundation will use
reinforced concrete separate foundation.
、：
Single-layer workshop with medium or small span: adopting light
steel portal frame; roof and wall will use profiling steel plate;
foundation will use reinforced concrete separate foundation.
Silo: clinker silo, cement silo and raw meal homogenizing silo, etc
will adopt site-casting reinforced concrete structure; foundation
will adopt ring-type reinforced concrete foundation,
round-plate-type reinforced concrete foundation or pile foundation.
Foundation of large equipment: for kiln, reinforced concrete
wall-type foundation is usually used; for mill and crusher,
reinforced concrete block foundation is usually used.
：
Conveying over-bridge: if not required by process specialty, open
structure with galvanized profiling steel plate belt covers will be
adopted for belt conveyor passages; pillar will use steel tube
structure; foundation will use reinforced concrete separate
foundation or pile foundation.
adopted.
4.5 Environment protection
4.5.1 Main pollution sources and pollutants
4.5.1.1 Mist and dust
Dust is the main pollutants of cement plant. It is generated in
material crushing, transporting, burning, grinding, storage and
packing, etc. Mist is mainly generated from gas pump at kiln inlet.
4.5.1.2 Waste gas
NOxSO2
Of the waste gas emitted at kiln inlet, Nitrogen oxides (NOx),
Sulphur dioxide (SO2), etc are poisonous gases which have bad
influences on environment.
4.5.1.3 Waste water
、
Drained sewage includes production sewage and living sewage.
Production sewage is mainly cooling water of equipment; living
sewage is mainly washing water and other organic sewage from
canteen and office building. Production sewage and living sewage
will be purified and reused.
4.5.1.4 Noise
80～115dB(A)
Noise sources are crushers, mills, air compressors and fans. Their
decibels are between 80 and115dB (A).
4.5.2 Pollution treatment measures
4.5.2.1 Treatment measures for mist and dust
To control emission of mist and dust and to reduce bad influences
on environment, several measures are taken. For example, choose
equipment which generates less dust; adopt close type conveying
equipment for powder; adopt close round silo for powder material
storage and decrease dropping distance of material
transferring.
50mg/Nm385m
Reliable and high-efficiency dust collectors are adopted at all
dust generated points. Dust amount and dust concentration is the
most at kiln inlet in this project, so high-efficiency electric
dust collector is selected. After purifying, dust emission at kiln
inlet is no more than 50mg/Nm3. it is drained by drainage pipe with
height of 85m.
4.5.2.2 Treatment measures for waste gas
SO2 SO2 (Sulphur dioxide)
SO2SO2SO298％12mg/Nm3
In reaction, Sulphur in raw materials and fuel will form into
Sulphur dioxide (SO2), which will emitted at kiln inlet. Sulphur
dioxide (SO2) emission is little because it will react with Calcium
oxide or other Basic oxide to produce Calcium sulfate or Calcium
sulfite and will leave in clinker. Sulphur absorption rate can
reach to 98％ if adopting new technology of pre-discomposing kiln.
According to preliminary calculation, Sulphur dioxide discharge in
this plan is about 12mg/Nm3. It complies with discharging standard
and can be discharged directly.
4.5.2.3 Noise control
、一
There are many noise sources. In order to control noise pollution,
low noise equipment should be chosen as possible. Mufflers are
adopted at both inlets and outlets of Roots blower and air
compressors. High noise resources are set far from boundary plant.
High noise resources are set in close or semi-close rooms.
Buildings and structures are used for noise preventing. By planting
trees and bushes at spare area can absorb some noise.
4.5.3 Greening
Greening is very useful in beautifying environment, absorbing dust
and noise and purifying air. Greening at both sides of road and in
sloping fields will be main greening measures, while greening in
spare area around workshops is auxiliary. Around stockyard which
can generate much dust, planting broadleaf trees and dust absorbing
trees can form the dust protective belt. Area around management
buildings and auxiliary production rooms is key greening place.
1.
Project investment estimated table
