Cement industries EHS consideration

CEMENT INDUSTRIES: EHS CONSIDERATIONS

A Presentation ByDr. V.C. SrivastavaAssistant Professor,Department of Chemical Engineering,Indian Institute of Technology Roorkee,Roorkee – 247667, India.Email: [email protected]

CEMENT INDUSTRIES: EHS CONSIDERATIONS: Dr. V.C. SrivastavaJanuary 25-29, 2010

INTRODUCTION

Cement production is yardstick for measurement of civilization and industrialization.

Significant role in providing shelter to mankind, infrastructural development of the nation.

The recent boom in infrastructure and the housing market.

Indian cement industry first bag of cement was packed in 1914 at Porbundar. ranks second next only to China

According to a report by the ICRA Industry Monitor, the installed capacity is expected to increase to 186 mt per annum (mtpa) by the end of FY 2008, and 219 mtpa by end of FY 2009, and further up to 241 mtpa by FY 2010-end.

As a result, India's cement industry will record an annual growth at around 10%.


Cement consumption 1985-2020E (million t)

Continent 1985 2003 2020% pa growth

03-20

Developed countries

323 410.5 475 0.80 %

Developing countries

363.7 1202.5 2586.5 4.30 %

Total 686.7 1612.9 3061.5 3.60 %


Indian cement industry Cement consumption per capita

India - 99 kg/capita (one of the lowest) China - 450 kg/capita. Japan - 631 kg/capita World average - 267 kg/capita.

Cement plants in our country have mostly changed from the wet process to the energy efficient dry process.

Indian industry matches quite well with world standards in terms of energy (thermal energy kcal/kg of clinker – India 665 against 690 of Japan) and pollution norms (SPM of 40 in India against 20 of Japan).

The average performance of the Indian industry is lagging behind.


PROCESS TECHNOLOGY

Alternative technologies: Wet process, Semi-dry process and Dry process.

Major steps in manufacturing Acquisition and transportation of raw materials Preparation of raw materials Pyroprocessing of raw materials to form cement clinker. Cooling and grinding of clinker with gypsum into cement Storage and packaging


ENVIRONMENTAL IMPACT


The raw materials for cement production are limestone or other source of CaCO3 (about 80 to 85%

of input), clay (about 15 to 20% of input), other (a few % of input) to provide Si, Fe and Al.

One needs approximately 1.5 kg of input material for 1 kg of cement output, the loss of mass being emitted as pollutant.

The fuel energy requirement is around 3700 MJ (1028 kWh) per tonne of clinker.

ENVIRONMENTAL HAZARADS AND

MANAGEMENT IN CEMENT INDUSTRIES


Environment Pollution due to Cement manufacture

Pollution causing activities of cement manufacture

Off Plant pollution In- plant pollution Application generated

Fugitive emissions


Environmental Impact of Cement Manufacture

A IR P O L L U T IO N : P a rtic u la te a n d Fu g itiv ee m iss io n ,S O x , N O x .

P L A N T P R O C E S SR a w M a te r ia l P re p a ra tio n , C ru sh in g a n d

G rin d in g , P yro p ro c e ss in g , C lin k e r C o o lin g ,C lin k e r a n d G yp su m g rin d in g .

R A W M A T E R IA L M IN IN GL im e S to n e , L a te r i te , B a u x ite , G yp su m , C o a l.

S T O R A G E A N D T R A N S P O R T A T IO N O FF IN IS H E D P R O D U C T

A IR P O L L U T IO N : P a rtic u la te s , Fu g it iv ee m iss io n ,S O x , N O x .S O L ID W A S T E : Fly A sh , E T P S lu d g e , re je c ts . A C ID IF IC A T IO NC O 2 E M M IS S IO NW A T E R P O L L U T IO N : B O D , C O D , T S S .

A IR P O L L U T IO N : P a rtic u la te a n d Fu g itiv ee m iss io n .

E IA /L C A


INTRODUCTION

Major environmental issues are dust pollution emission of Green House Gases (GHG), ecological concern arising from the degradation of mined-out areas, noise and transport pollution.

Cement related GHG emissions originate from fossil fuel combustion at cement manufacturing operation (40%) transport activities (5%) combustion of fossil fuel that is required to make the electricity (5%). Other manufacturing process (about 50%)


ENVIRONMENTAL ISSUES

Fugitive emissions are quite high in cement industries and requires immediate attention for control.

Continuous dust monitoring system with data logger should be installed by all the cement industries and calibration should be done from time to time.

Pet-coke containing about sulphur is being used as fuel in cement kiln in few units. The SO2 emission vanadium and nickel emission.

It is necessary to frame fuel quality specifications for the cement industries.


ENVIRONMENTAL ISSUES

Emission standards for particulate matter is quite relaxed in comparision to other countries like USA, Japan, Germany. Need is being felt to revise the emissions standards.

Cement industries have potential to utilise industrial wastes like flyash, blast furnace slag, phosphogypsum. But the present utilization is low and needs to be enhanced.

In Indian cement industries, 40% of total heat input is going as waste heat, which should be utilized for co-generation of power. This is already being practiced in Japan, China & South East Asian Countries.

The need of identifying incinerable hazardous waste for use as fuel in cement kiln is also stressed.


List of impact categories Type Impact category Unit Spatial Scope Squandering of resources

Abiotic resources - Global

Biotic resources Year-1 Global/regional Land - Local Pollution Global warming kg CO2-eq. Global Depletion of the ozone

layer kg CFC-11 eq. Global

Human toxicity kg b.w.a Global/continental/regional/local Aquatic ecotoxicity m3 polluted watera Global/continental/regional/local Terrestrial ecotoxicity kg polluted soila Global/continental/regional/local Photochemical

oxidantformation kg C2H4-eq. Continental/regional/local

Acidification kg SO2-eq. Continental/regional/local Eutrophication kg P-eq. Continental/regional/local Waste heat MJ Regional/local Odour m3 polluted aira Local Noise Pa2*s Local Affection Ecosystem and

landscape m2·s Global/continental/regional/local

Death — Local aPolluted to a defined threshold level.


Pollutants Released by Cement Kilns

Carbon dioxide (global warming gas) Acid Gases, Nitrogen Oxides, Sulfur

Dioxide, Particulate Matter 19 heavy metals, including lead, mercury,

cadmium and chromium VI Products of Incomplete Combustion (PICs),

including dioxins, furans and Polycyclic Aromatic Hydrocarbons (PAHs)

Source: http://www.texascenter.org/publications/kiln.htm


Pollutants Released by Cement Kilns

“Upset” events in cement kilns operation trigger increased emissions from the stack and “fugitive” (non-stack) emissions from the cement kiln itself.

When handling, storing and burning liquid hazardous wastes, fugitive emissions can be released from numerous points at ground level such as the seals on the cement kiln, vents and pressure release valves, the storage tanks, and transfer points from the storage tanks through the pumps and into the rotary kiln.


Dioxin Facts

Dioxins and furans are the most toxic chemicals known to science

Dioxins cause infertility, learning disabilities, endometriosis, birth defects, sexual reproductive disorders, damage to the immune system, cancer and more.

93% of dioxin exposure is from eating meat and dairy products.


How to make dioxin

Dioxins are created by burning hydrocarbons (fossil fuels, tires, hazardous wastes) with chlorine (present in coal, tires and some hazardous wastes) in the presence of oxygen.

Dioxin emissions increase when:More chlorine is in the fuel/waste streamCertain metal catalysts are presentThe gases stay in a low temperature range (200-

450o C)


Continuous Emissions Monitors

www.ejnet.org/toxics/cems.html

Ammonia (NH4)

Carbon Dioxide (CO2)

Hydrogen Sulfide (H2S)

Acid Gases:Sulfuric Acid (H2SO4)Hydrofluoric Acid (HF)Hydrochloric Acid (HCl)

Products of Incomplete Combustion (PICs):Dioxins & FuransPolycyclic Aromatic Hydrocarbons (PAHs)Volatile Organic Compounds (VOCs)

Metals:Antimony (Sb)Arsenic (As)Barium (Ba)Cadmium (Cd)Chromium (Cr)Lead (Pb)Manganese (Mn)Mercury (Hg)Silver (Ag)Nickel (Ni)Zinc (Zn)…and more

• Only generally used for sulfur oxides (SOx), nitrogen oxides (NOx), oxygen (O2), carbonmonoxide (CO) and opacity (indirectly monitoring particulate matter)

• Technology now exists to continuously monitor:


Cement Kiln Dust (CKD)

Large amounts of fine material given off and carried out by flow of hot gas within cement kiln

Collected using pollution control systems like cyclones, electrostatic precipitators, or baghouses, and is then landfilled either on or off site.

Dry process cement kilns generally produce more CKD

Some CKD is “recycled” into the cement product.


“Beneficial” Uses

Not considered hazardous waste by US EPA Soil Stabilization Stabilization and Solidification of Waste Cement Replacement Asphalt Pavement Mine Fill Crop Enhancer


What’s in Cement Kiln Dust?

Calcium Oxide Toxic metals: Arsenic, Chromium, Cadmium,

Antimony, Barium, Beryllium, Lead, Silver, Mercury, Thallium, Selenium, Nickel

Dioxin, Furans


Cement Kiln Dust More Toxic when Burning Hazardous Waste

Hazardous Waste Fuels vs. Traditional Fuels Hazardous Waste either emitted into air, absorbed into

CKD, or into clinker (final product) Using hazardous waste produces 104% more cement

kiln dust by volume Lead concentrations 250% higher Cadmium concentrations 150% higher Chromium concentrations 50% higher Selenium concentrations 100% higher 700 times more dioxinSource: EPA, Report to Congress on CKD, December 1993)Source: Downwinders (http://www.downwindersatrisk.org/DownwindersAtRisk-

100FactsAboutTheIncineration.htm)


Cement Industry & Green house Gas (GHG) Emissions

5% of global man-made CO2 emissions Cement industry's emission of CO2 is next only to thermal

power plants (coal based). The approximate contributions of each of the CO2 sources are:

Calcination 50 - 55% Fuel combustion 40 - 50% Electricity 0 - 10%

Total CO2 emissions per tonne of cement (assuming a 0.95:1 clinker to cement ratio) ranges about from 0.85 to 1.15 tonne.


Limiting CO2 emissions

Process modification Substitution of coal by lower carbon fuels like

lignite and natural gas, Use of washed coal, Improved kilns, Use of renewable sources of energy like solar,

wind energy also come under this category. Afforestation and planting of trees in the plants'

environs; these act like a "sink" for GHG's.


Limiting CO2 emissions

Product modification Blended cement manufacture Increased use of pozzolana in concrete. Lower clinker contentIncrease fuel efficiencyAlternative fuels


Improved Waste ManagementUsing Cement Kilns to Manage Waste Problems

High temperature, long residence time Well controlled process Can safely process alternative materials with

appropriate handling, training and safety procedures More than 10 million tons of Hazardous Wastes is

co-processed in cement kilns annually Potential use to dispose of off-date pesticides

(approx. 500 mil pounds worldwide) Potential to provide sound disposal option for many

wastes in India.

HEALTH HAZARADS AND MANAGEMENT IN CEMENT INDUSTRIES


Health Issues

The main health hazards which may have implications for health are as follows:

Airborne dust Noise and vibration Dangerous atmospheres Handling of alternative fuels

The incidence of such over exposure is generally so low as not to require statistical monitoring or reporting.

No universal industry standard yet exists on monitoring and reporting.


Guidelines on Specific Health Issues

Airborne Dust Cement production produces dust that without effective control

leads to respiratory disease. There are some indications of elevated chronic obstructive lung

diseases.

GOOD PRACTICE Limit dust levels, and employee exposure. Appropriate respiratory protection should be worn where work

has to be carried out in dusty areas in cement plants.

Various limits exist in different countries Exposure limits for Respirable Crystalline Silica are now under

review.


Guidelines on Specific Occupational Health Issues

Noise and Vibration Main sources of noise are the milling plants used to

grind the cement product. PPE are required for noise levels below 80 dB. Noise deflectors and improved sound insulation. Improved noise personal protective equipment Workers to wear appropriate hearing protection. Many companies regularly monitor employee

auditory functions to ensure this does not exceed natural decline with age.



Noise and Vibration Whole body vibration is another issue. Workers driving older heavy mobile equipment can

be exposed to vibration. Modern mobile equipment combine

lower inherent vibration with damped seating and insulated cabins, reducing the hazard

to insignificant levels.



Dangerous Atmospheres Coal and petroleum coke mill areas, where fine

airborne particles can create an explosion hazard.

Kiln and raw mill cyclones and ducting, where un-ventilated process gases could lead to a shortfall of oxygen during maintenance work.



Dangerous Atmospheres

Working in Coal/Petroleum Coke Processing Areas Quantities of coal or coke may self-ignite, if conditions allow,

leading to the possibility of bursting into flame avoid spillages where possible clean up spillages as soon as they occur.

A mixture of coal dust or coke dust and air is potentially explosive, leading to the possibility of a violent blast avoid creating dust clouds remove source of ignition such as glowing coal, sparks, welding,

grinding, static, electricity, smoking etc. Smoking must be strictly forbidden at all times throughout all the coal

processing areas



Environmental Health Cement-making raw materials do sometimes contain

trace amounts of toxic elements such as mercury, thallium, iodine, cadmium and other heavy metals.

Stack emissions are monitored where appropriate for these trace components.

The cement-making process can also lead to trace emissions of POP’s (Persistent Organic Pollutants).



Handling of Alternative Fuels Plastics: Recycled plastics are normally used

in shredded form and conveyed pneumatically. There can be considerable associated dust

requiring eye protection and breathing masks as well as full body clothing, metal silos and ducts need electrical earthing to prevent an explosion hazard.

Fire protection is also required, as well as evacuation instruction in the case of fire, as smoke vapours can be toxic.



Handling of Alternative Fuels Solvents:

Recycled solvents must be rigorously sampled at intake because of variable chemical and physical composition in order to determine health precautions.

Most solvents are toxic and may be flammable. Therefore health precautions are similar to those used in the source industry (e.g. chemical, pharmaceutical) Intake and storage systems must be designed for safe, automated handling, with spill, fire and explosion protection, with an associated emergency plan.

Health procedures require eye protection, breathing masks and full cover clothing.

Used Oils & Oil Emulsions : Used oils will need to be checked for PCB content that will determine

precise precautions required. Requirements are generally similar to those for solvents, with similar

health precautions.



Handling of Alternative Fuels Sewage Sludge:

While sewage sludge is generally pre-treated there is a possibility of biological infection.

Hence the main emphasis is on avoidance of skin contact and skin protections through use of gloves and appropriate clothing, followed by usual employee hygiene precautions afterwards.

This listing of secondary fuels is indicative only. In general, rules for handling these and any other

materials should be equivalent to those used in the industry from which these are sourced.



Other General Guidelines are: All operating personnel should have a thorough knowledge of

methods for competent operation of the fuel handling systems in normal operation, startup, shutdowns and emergency situations.

Persons handling fuels should be advised of hazards, proper procedures, precautions, health effects and recommendations for emergency treatment.

An emergency plan should adequately address possible emergencies that may arise during transport, storage, handling, and processing.

An emergency shower and eye washing station should be clearly marked and located near the storage areas of liquid and alternative fuels.


Other possible health risks

Health risks due to vermin and others pests can arise particularly in warmer countries due to unhygienic conditions and due to storage of secondary fuels such as tyres.

Minor quantities of toxic chemicals may also be used in the manufacturing process. These include laboratory chemicals and other cleaning fluids and solvents.

Transformers and capacitors may also contain PCB (Poly-Chloro-Biphenyl) liquids.


Product related health risks

Due to its properties, e.g. the high pH value, the handling of cement has to be done carefully.

Material Safety Data Sheets (MSDS) enable users of cement to take the necessary measures relating to protection of health and safety in the workplace.

Persons placing substances and preparations on the market should ensure that persons, coming in contact with cement, have received appropriate training and use the protective equipment correctly.

Special attention has to be paid to skin protection eye protection protection of the respiratory system.

SAFETY HAZARADS AND MANAGEMENT IN CEMENT INDUSTRIES


Fatality Analysis

A fatality anaylsis data from a number of Cement Sustainability Initiative (CSI) members was collected and analysed. It was found that:

There was a total of 389 Fatalities in ~300,000 employed over (2003-2007)

79% of all fatalities arise from 3 main causes Traffic & Mobile Plant (43%) Falls from Heights & Items falling (21%) Caught in Moving/Starting Equipment (15%) Others were…


Fatality Analysis


Fatality Analysis

Fatalities by Age, hour, day and month, work category

Employee Fatalities peak in 30’s & 40’s Contractor Fatalities peak in later 40’s & 50’s Third Party Fatalities peak in the teens Data collected also show: Highest Peak fatality time

is 10am to Noon More fatalities occur on Monday than on any other

day of the week Peak injury rates occur in January & March,

possibly related to cold weather conditions Drivers account for nearly 50% of the fatalities


Conclusion: Fatality Causes & Prevention

High Risk Categories: Prevention:

Contractors Contractor Safety Management

Young/Temporary Employees Special Safety Induction

Direct Causes

Traffic & Mobile Plant (43%) Driver Training

Falls from Heights, Objects falling from Heights (21%)

Safety Procedures for Work at Heights, Overhead Protection

Caught in Starting/Moving Equipment (15%)

Plant Isolation Procedures


Lost Time Injury Analysis

Typical Injury Causes & Types Main causes are Slips, Trips and Falls (29%), Falling or Moving Objects (19%) and Lifting, Overload and Exertion (18%).

These three causes account for 66% of the total accidents.

Most Injuries are to Arms and Hands (32%), Legs and Feet (25%) and Back (13%)

These injuries are 71% of the total


Lost Time Injury Analysis


Most Injuries are to Arms and Hands (32%), Legs and Feet (25%) and Back (13%)

These injuries are 71% of the total Typical Injury Categories and Ages Plant Operators (39%) and General Operatives

(33%) are the most injury prone. 30-39 is the most injury prone age range

(33%), followed by 20-29 (25%), and 40-49 (24%)


Conclusion on Injury Causes & Prevention

Injury Causes: Prevention:

Slip, Trips & Falls Housekeeping, clear designatedwalkways

Falling/Moving Objects Guards on Machines and elevated areas

Lifting & Overload Manual Handling Training

Injury Types

Arms and Hands Proper use of Personal Protective Equipment (PPE)

Legs and Feet Proper use of PPE

Back Injuries Lifting gear, lifts


Good Practices in Safety

Mobile Plant Common hazards associated with the heavy plant

(e.g. dumper trucks, front loading shovels, fork lift trucks) used in quarrying and bulk material transport include vehicle impact and twisted ankles during embarking and disembarking.

Incidents can be reduced by improved driver training, increasing awareness of the people working alongside these

vehicles, and by using dedicated routes and crossings. Modern vehicles also offer improved visibility, helping

further reduce the risks.



Working at Height Controls relating to working

at height or in confined areas (e.g. Permit-to-work)

Mandatory use of safety equipment (harnesses, safety nets) to properly protect workers from falls, posting of permits.



Slips, Trips and Falls A nut or bolt falling from a height can kill a person REMEMBER

THAT Keep work places tidy Use the scrap and dirt bins where provided Pile material so that it is stable and steady Put tools and other equipment where they can not possibly fall or be

knocked on to someone below. Clearly mark, fence or cover all openings in floor, roof or ground. All excavations in the plant should be surrounded with a handrail When working overhead remove all loose material such as bolts,

screws, tools, timbers, fittings, etc. when the job is finished. Never throw tools or materials, always pass them from hand to hand.



Fire As a generality, there are few combustible materials

in the process equipment in a cement plant, with the exception of conveyor belts.

Several cases of significant conveyor belt fires have arisen, where belt misalignment and/or friction caused heat build-up and subsequent ignition. Heat detectors may be used at conveyor tension stations,

and belts may be purchased made of less/noncombustible material, to lessen the risk of fire. Fire fighting procedures must also be in place.

Electrical cables may also cause or transmit a fire, also with emission of highly toxic smoke.



Fire Storage of fuels of all types must be in accordance

with local fire regulations and good practice. This applies also to external stockpiles of coal, pet-

coke, tyres and the like, where appropriate fire precautions will be required, particularly in hot dry weather.

Storage of waste combustible materials will create a fire hazard.

Proper waste disposal and good housekeeping is the best form of prevention.



Entry into Silos and Confined Spaces A confined space is any space of an enclosed nature

where there is a risk of death or serious injury from hazardous substances or dangerous conditions. The risks in confined spaces arise due to Lack of oxygen Poisonous gas, fumes or vapour Liquids and solids, which can fill the space suddenly Fire and explosions Dust Hot conditions



Avoid entry to confined spaces, e.g. by doing the work from outside

Blockages can be cleared in silos by use of remotely operated rotating flail devices, vibrators or air purgers

Inspection, sampling and cleaning operations using the right equipment Remote cameras can be used for internal inspection of vessels

If entry is unavoidable, follow a safe system of work Appointment of supervisor Cleaning before entry Check the size of the entrance Provision of ventilation Testing the air Provisions of special tools and lighting Provision of breathing apparatus



Electrocution As cement plants are very energy intensive, there will

be significant power distribution equipment in all plants.

Electrical maintenance must be conducted on a professional basis.

Machine Guarding Where there is a risk of physical contact with moving

parts of work equipment which could lead to injuries, those parts must be provided with guards or devices to

prevent access to danger zones.



Heat Burns Incidents and injuries resulting in burns arise from

contact with hot clinker or cement powder. Hazards are particularly associated with hot cement kiln dust (CKD), and dust on preheater systems.

Contact is possible during abnormal operation of the plant, when clearing blockages, carrying out maintenance or in emergency situations.

From contact with combustible materials; oils, scaffold boards, ladders, electrical cabling, etc.



Raw Mill and Preheater Tower: Material in the mill is at temperatures up to 120ºC, in the tower the material can be as hot as 900ºC. Contact is more likely when:

Clearing blockages in the tower where there is the potential for it to flush through the process

Hot Clinker: Contact is possible in the: clinker cooler building along the clinker pan conveyors in the clinker dome along the belts to the cement mills



Precipitator and By-Pass Dust: access is required to the precipitator hoppers working on the screws and drag chain conveyors maintaining the dust transfer pumps

Hot Cement: Contact is possible when: accessing the cement transfer lines working on the packers carrying out work on the cement screw conveyors and

drag chains


Control / Management of the risks

Eliminate the hazard Reduce the risk at source Isolate people from the hazard Control the risk by other means Protect with the correct PPE

Other Good Practices The use of “high visibility” clothing is strongly recommended

particularly under poorer lighting conditions. Good lighting around cement plants is also a pre-requisite for

safety of night-time operation and maintenance activities. Use of mobile phones should be restricted in areas where

inattention could cause serious consequences.


Life saving rules

Any person working on equipment with moving parts must personally ensure the equipment is de-energized, isolated and locked/tagged out

Any person working from a position with the potential for a fall of 1.8 meters or more must use fall protection

Any person doing flame welding, cutting or brazing up to 6 meters from any flammable material must obtain a proper hot work permit and apply the requirements

Any person entering a confined space must obtain a proper confined space entry permit and apply the requirements

Prescribed PPE shall always be worn when exposed to open processes or systems (e.g. clearing material blockages, electrical work, etc …)

Using illegal drugs is strictly forbidden on any site - use of alcohol or other legal drugs that can effect personal concentration is discouraged


GLOBAL ISSUSE FACING THE CEMENT INDUSTRIES


SUSTAINABLE DEVELOPMENT OF CEMENT MANUFACTURE


STEPS TOWARDS SUSTAINABLE CEMENT PRODUCTION...

No Management (Business as Usual)No Management (Business as Usual) Solid Waste DisposalSolid Waste Disposal

Effluent TreatmentEffluent Treatment Waste ManagementWaste Management Conservation of WaterConservation of Water Conservation of EnergyConservation of Energy

Safety Safety ManagementManagement

Health ManagementHealth ManagementEnv. ManagementEnv. Management Cleaner ProductionCleaner Production

Industrial EcosystemIndustrial Ecosystem

CONCLUSIONCONCLUSION


CONCLUDING REMARK

If construction is considered as the mother of "Development", the cement industry is the grandmother.

Being the grandmother, she has an obligation not only to preach, but practice the concept of ‘SHE' and that too effectively, economically and elegantly.

THANK YOU

Education

Cement industries EHS consideration