Process
Value added product, classified fly ash
Published
5 years agoon
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adminDirk India Pvt Ltd (Unit of Ambuja Cement Limited) is in the business of classification of fly ash and manufacturing PPC by the method of intermixing. Fly ash is being classified by centrifugal cyclone separators to various micron size constitutes to different grades of fly ash known as Pozzocrete. This Pozzocrete is sold under various brand names of P100, P63 and P60 depending upon particle size of fly ash. P100 (Microfine Fly Ash) is basically used for High Performance Concrete starting from M60 and above and Pozzocrete P63 grade of concrete is used for M40 to M60 and P60 is used for normal grade of concrete. Coarse material known as P10 is now used in making bricks and blocks as well as partial replacement of sand. Presently, P100 and P63 had been extensively used by Builders and RMC Industries for their large and small projects including infrastructure projects. The possibility of using P10 (less than Blaine 150 m2/Kg) had been studied by grinding the coarse fly ash to the desired Blaine. The same has also been tried in lab ball mill to achieve different fineness and its Lime Reactivity Testing have been checked and lab scale PPC have been prepared by the method of inter-mixing to see the performance in cement and concrete. At the same time, ground fly ash and classified fly ash of identical Blaine have been compared to see their relative properties in their performance both in mortar and concrete.
1.0 History
Over the years there has been a growing demand for finer, more accurately sized and Quality Assured particulate-materials to meet the material specifications of industry. To some extent this has been due to a better understanding of the function that the complete particle size distribution of a material and not just some aspect of it contributes to the performance of a powder when applied to a particular process. The ash – produced Pulverised fuel ash( fly ash) / by product – quality varies widely dependant on fuel source and quality variations on plant design, combustion and dust collection processes, plant engineering and plant operational practice International Standards for Cement Replacement Materials dictate that chemical, physical and particle size characteristics should be controlled. These characteristics are not a part of all the Pulverised fuel ash produced by coal fired power stations. Hence it becomes necessary to Process the Pulverised fuel ash by using the technology that produces the product that confirms stringent requirements laid out by various international standards. The high performance concrete includes all those types of concrete with special requirements such workability, pump ability, high flow and higher retention in fresh state and high strength and high durability in Solid state. Classified fly ash has very high potential to produce all these types of Concrete effectively. At the same time one needs to ensure right Particle size as well as Particle size distribution which can only be achieved by state of art classification systems similar to one of those installed at Dirk India private Limited. By choosing right type of fly ash one can precise+ly produce High Volume fly ash mixes (Fly ash % above 40%) event at Low grade and normal grade concrete as well as normal replacement levels for High early strength mixes.
2.0 Objective
As the Processed Pulverised fuel ash needs to undergo a process which will not change the geometry of the tiny particles as the shape, which is spherical, plays very important role in the concrete. This ensures that the chemistry of the ash is not changed. Apart from this the ash needs to be processed in large volumes and at minimum cost and also in environmental friendly manner. Our long experience lead us to Mechanical Air Classifier which met all the requirements of processing the fly ash.
2.1 Description of the Equipment (Classifier) Mechanical Air Classifier works on the principle that wherever relative motion exists between a particle and a surrounding fluid, the fluid will exert a drag force on the particle. If the individual particle was falling under the influence of gravity in still air, it would accelerate until it reached a constant velocity which is known as the Terminal Settling Velocity. This occurs when the drag force exerted by the air balances the gravitational force exerted on the particle. This velocity rises the air thus the smaller particles of lower terminal settling velocity is entrained and carried upwards. Since the difference in terminal settling velocity between particles in the sub sieve range (fine powders) becomes so small, then a simple gravitational system becomes impractical. To overcome these limitations it is necessary to increase the gravitational force in this way the air velocity necessary for the entrainment of a given particle is increased, the difference between particles magnified and high efficiency classification becomes possible in a relatively small space.
Figure no 1: Typical Cross Section of a High Efficiency Side Draft DIRK Classifier.
In practice this is achieved by causing the carrying air and particles to follow a curved path which spiral inwards to a concentric discharge point. In this way forces of several hundred gravities may be generated
and consequently high capacity and precise separation achieved in relatively small machines. The inside view (Figure No 1) shows the particle separation process which takes place inside this tiny equipment. As the operating parameters are controlled by PLC, the processed ash particle size range remains precisely within the set parameters thus ensuring the consistency of the product irrespective of the varying feed material particle size range and volume.
3.0 Nomenclature and properties of different grade of fly ash
3.1 Nomenclature of different classified flyash
On the basis on above classification, materials are recovered with different Blaine fineness and residue on 45? sieve and nomenclature of different grade of flyash mentioned in Table no 1
Table No 1: Nomenclature of differentgrade of fly ash
Grade |
P10 |
P20 |
P30 |
P40 |
P60 |
P63 |
P73 |
P83 |
P100 |
Blaine Fineness (m2/kg) |
100 |
225 |
260 |
300 |
320 |
400 |
450 |
500 |
625 |
Residue on 45? sieve (%) |
75 |
38 |
33 |
25 |
18 |
10 |
4.5 |
3 |
0 |
3.2 Properties of Classified Flyash
3.2.1 Chemical Properties of Classified Flyash
Flyash of different grade are collected and tested for chemical (IS 4031: 1988) and Physical properties (IS 4032:1985). Chemical & Physical Test results are mentioned in Table No 2 & 3 respectively.
Table No 2: Chemicalproperties of classified fly ash
Name of the Tests |
IS:3812-2013 (Part-I) Requirement |
P10 |
P20 |
P30 |
P40 |
P60 |
P63 |
P73 |
P83 |
P100 |
Reactive Silica (%) |
20 % (Min) |
20 |
23 |
24 |
26 |
29 |
32 |
36 |
40 |
46 |
Reactive Silica increases with increase in Blaine Fineness from P10 to P100 from 20% to 46%
3.2.2 Physical Properties of Classified Flyash
Physical testing of all the classified flyash of different grade are carried out at Dirk Plant Laboratory at Nashik as per IS IS 4031: 1988 and IS-1727:1967. Results were reported in Table no 3 with reference to specification in IS-3812 part 1 (2013).
Table-3 : Physicalproperties of classified fly ash of different grade
Name of the Tests |
Fineness-Specific surface |
Residues on 45 Micron |
Moisture Content |
Soundness by Autoclave
ProcessPrice hikes, drop in input costs help cement industry to post positive margins: Care RatingsPublished 3 years agoon October 21, 2021By adminRegion-wise,the southern region comprises 35% of the total cement capacity, followed by thenorthern, eastern, western and central region comprising 20%, 18%, 14% and 13%of the capacity, respectively. The cement industry is expected to post positive margins on decent price hikes over the months, falling raw material prices and marked drop in overall production costs, said an analysis of Care Ratings. Wholesale and retail prices of cement have increased 11.9% and 12.4%, respectively, in the current financial year. As whole prices have remained elevated in most of the markets in the months of FY20, against the corresponding period of the previous year. Similarly, electricity and fuel cost have declined 11.9% during 9M FY20 due to drop in crude oil prices. Logistics costs, the biggest cost for cement industry, has also dropped 7.7% (selling and distribution) as the Railways extended the benefit of exemption from busy season surcharge. Moreover, the cost of raw materials, too, declined 5.1% given the price of limestone had fallen 11.3% in the same aforementioned period, the analysis said. According to Care Ratings, though the overall sales revenue has increased only 1.3%, against 16% growth in the year-ago period, the overall expenditure has declined 3.2% which has benefited the industry largely given the moderation in sales. Even though FY20 has been subdued in terms of production and demand, the fall in cost of production has still supported the cement industry by clocking in positive margins, the rating agency said. Cement demand is closely linked to the overall economic growth, particularly the housing and infrastructure sector. The cement sector will be seeing a sharp growth in volumes mainly due to increasing demand from affordable housing and other government infrastructure projects like roads, metros, airports, irrigation. The government’s newly introduced National Infrastructure Pipeline (NIP), with its target of becoming a $5-trillion economy by 2025, is a detailed road map focused on economic revival through infrastructure development. The NIP covers a gamut of sectors; rural and urban infrastructure and entails investments of Rs.102 lakh crore to be undertaken by the central government, state governments and the private sector. Of the total projects of the NIP, 42% are under implementation while 19% are under development, 31% are at the conceptual stage and 8% are yet to be classified. The sectors that will be of focus will be roads, railways, power (renewable and conventional), irrigation and urban infrastructure. These sectors together account for 79% of the proposed investments in six years to 2025. Given the government’s thrust on infrastructure creation, it is likely to benefit the cement industry going forward. Similarly, the Pradhan Mantri Awaas Yojana, aimed at providing affordable housing, will be a strong driver to lift cement demand. Prices have started correcting Q4 FY20 onwards due to revival in demand of the commodity, the agency said in its analysis. Industry’s sales revenue has grown at a CAGR of 7.3% during FY15-19 but has grown only 1.3% in the current financial year. Tepid demand throughout the country in the first half of the year has led to the contraction of sales revenue. Fall in the total expenditure of cement firms had aided in improving the operating profit and net profit margins of the industry (OPM was 15.2 during 9M FY19 and NPM was 3.1 during 9M FY19). Interest coverage ratio, too, has improved on an overall basis (ICR was 3.3 during 9M FY19). According to Cement Manufacturers Association, India accounts for over 8% of the overall global installed capacity. Region-wise, the southern region comprises 35% of the total cement capacity, followed by the northern, eastern, western and central region comprising 20%, 18%, 14% and 13% of the capacity, respectively. Installed capacity of domestic cement makers has increased at a CAGR of 4.9% during FY16-20. Manufacturers have been able to maintain a capacity utilisation rate above 65% in the past quinquennium. In the current financial year due to the prolonged rains in many parts of the country, the capacity utilisation rate has fallen from 70% during FY19 to 66% currently (YTD). Source:moneycontrol.com ProcessWonder Cement shows journey of cement with new campaignPublished 3 years agoon October 21, 2021By adminThe campaign also marks Wonder Cement being the first ever cement brand to enter the world of IGTV… ETBrandEquity Cement manufacturing company Wonder Cement, has announced the launch of a digital campaign ‘Har Raah Mein Wonder Hai’. The campaign has been designed specifically to run on platforms such as Instagram, Facebook and YouTube. #HarRaahMeinWonderHai is a one-minute video, designed and conceptualised by its digital media partner Triature Digital Marketing and Technologies Pvt Ltd. The entire journey of the cement brand from leaving the factory, going through various weather conditions and witnessing the beauty of nature and wonders through the way until it reaches the destination i.e., to the consumer is very intriguing and the brand has tried to showcase the same with the film. Sanjay Joshi, executive director, Wonder Cement, said, "Cement as a product poses a unique marketing challenge. Most consumers will build their homes once and therefore buy cement once in a lifetime. It is critical for a cement company to connect with their consumers emotionally. As a part of our communication strategy, it is our endeavor to reach out to a large audience of this country through digital. Wonder Cement always a pioneer in digital, with the launch of our IGTV campaign #HarRahMeinWonderHai, is the first brand in the cement category to venture into this space. Through this campaign, we have captured the emotional journey of a cement bag through its own perspective and depicted what it takes to lay the foundation of one’s dreams and turn them into reality." The story begins with a family performing the bhoomi poojan of their new plot. It is the place where they are investing their life-long earnings; and planning to build a dream house for the family and children. The family believes in the tradition of having a ‘perfect shuruaat’ (perfect beginning) for their future dream house. The video later highlights the process of construction and in sequence it is emphasising the value of ‘Perfect Shuruaat’ through the eyes of a cement bag. Tarun Singh Chauhan, management advisor and brand consultant, Wonder Cement, said, "Our objective with this campaign was to show that the cement produced at the Wonder Cement plant speaks for itself, its quality, trust and most of all perfection. The only way this was possible was to take the perspective of a cement bag and showing its journey of perfection from beginning till the end." According to the company, the campaign also marks Wonder Cement being the first ever cement brand to enter the world of IGTV. No other brand in this category has created content specific to the platform. ProcessIn spite of company’s optimism, demand weakness in cement is seen in the 4% y-o-y drop in sales volume. (Reuters)Published 3 years agoon October 21, 2021By adminCost cuts and better realizations save? the ?day ?for ?UltraTech Cement, Updated: 27 Jan 2020, Vatsala Kamat from Live Mint Lower cost of energy and logistics helped Ebitda per tonne rise by about 29% in Q3 UltraTech Cement Better realizations during the December quarter, in spite of the 4% year-on-year volume decline, minimized the pain. Net stand-alone revenue fell by 2.6% to ?9,981.8 crore. But as pointed out earlier, lower costs on most fronts helped profitability. The chart alongside shows the sharp drop in energy costs led by lower petcoke prices, lower fuel consumption and higher use of green power. Logistics costs, too, fell due to lower railway freight charges and synergies from the acquired assets. These savings helped offset the increase in raw material costs. The upshot: Q3 Ebitda (earnings before interest, tax, depreciation and amortization) of about ?990 per tonne was 29% higher from a year ago. The jump in profit on a per tonne basis was more or less along expected lines, given the increase in realizations. "Besides, the reduction in net debt by about ?2,000 crore is a key positive," said Binod Modi, analyst at Reliance Securities Ltd. Graphic by Santosh Sharma/Mint Kunal Shah, analyst (institutional equities) at Yes Securities (India) Ltd, said: "The company has proved its ability of asset integration. Century’s cement assets were ramped up to 79% capacity utilization in December, even as they operated Nathdwara generating an Ebitda of ?1,500 per tonne." Looks like the demand weakness mirrored in weak sales during the quarter was masked by the deft integration and synergies derived from these acquired assets. This drove UltraTech’s stock up by 2.6% to ?4,643 after the Q3 results were declared on Friday. Brand transition from Century to UltraTech, which is 55% complete, is likely to touch 80% by September 2020. A report by Jefferies India Pvt. Ltd highlights that the Ebitda per tonne for premium brands is about ?5-10 higher per bag than the average (A cement bag weighs 50kg). Of course, with competition increasing in the arena, it remains to be seen how brand premiumization in the cement industry will pan out. UltraTech Cement scores well among peers here. However, there are road bumps ahead for the cement sector and for UltraTech. Falling gross domestic product growth, fiscal slippages and lower budgetary allocation to infrastructure sector are making industry houses jittery on growth. Although UltraTech’s management is confident that cement demand is looking up, sustainability and pricing power remains a worry for the near term.
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