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Process & quality optimisation in cement plant

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Various process instruments have made the job of quality control relatively easy in cement plants. Dr Bibekananda Mohapatra takes into the details of various instruments and the parameters that can be controlled. This is second part of the article. Part 1 was published in the last edition.

The relationship between the burning condition of cement clinker and the ultimate cement properties is well established and being so, determination of burning condition is important in controlling the cement quality. Examination of a large number of cement clinkers from different plants and laboratory clinkers demonstrate that the ratio between the diffraction lines, corresponding to "d" 2.78+ (2?=32.2) and "d"2.74+ (2?=32.7) bears a distinct relationship with the clinkering process. The characteristic of these two lines (d values) is that both of them are combined products of alite (C3S) and belite (C2S) and in case of perfect crystallisation, they bear a ratio of 1 to 1.1 only, termed as "C" index [Lea, 1970]. From the examination of industrial clinkers from different plants, it is observed that to achieve normal cement properties, the "C" index must not be above 1.5 [Goswami and Panda, 1986; Goswami et.al, 1991; Goswami et.al, 2016]. Thus "C" index reflects the degree of crystallisation, and the higher the "C" index, lesser is the degree of crystallisation.

Accordingly, there exists a distinct relationship between the "C" index, burning condition and degree of crystallisation of cement phases. As the burning condition determines the cement quality, the "C" index can be used directly for predicting the cement properties. For example, during the production of the clinker with "C" index ranging from 1.6 to 3.7 (Table 3), the kiln atmosphere was very dusty, and the cement produced showed abnormal properties. Cement from kiln-2 and 3 was of normal quality, while that of the kiln-3 was the best product. This provides a good relationship between "C" index and clinker quality.

Table 3: ‘C’ indices of cement clinkers fromdifferent sources

No. of samples analysed

‘C’ index

Range

Average

Kiln-1

Early stage-disturbed

15

1.6-3.7

2.5

Later stage-smooth running

35

1.2-2.4

1.5

Kiln -2

20

1.1-1.7

1.4

Kiln-3

25

1.0-2.1

1.2

Evaluation of clinker (potential vis-a-vis actual cement phases) Mineralogy of the cement clinker determines cement properties. It is well known that very often cement clinkers having almost identical chemical composition produce cement of varying properties. This generally happens because of changes in mineralogy due to the presence (absence) of some minor constituents, and mineralisers, a trace of which can alter the mineralogy of the clinker, which was not detected by the widely known oBogueo calculation, based on major oxide constituents.

It is generally observed that clinker phases determined by XRD and optical microscopy were different in comparison to Bogue calculations, indicating that the quality of clinker entirely depends on the phase composition, and could be determined more precisely only by quantitative XRD. Although, XRD and microscopic analysis produce almost similar values, the former is having number of advantages over the later [Goswami et.al, 1992]

During the use of petcoke as a prime fuel in cement plants, along with the main mineral phases of the clinker like C3S, C2S, C3A, C4AF, various other associated minerals are characterized by XRD like anhydrite (CaSO4), aphthitalite (3K2SO4. Na2SO4), arcanite (K2SO4), calcium langbeinite (K2SO4 2CaSO4) and thenardite (Na2SO4).

Overall sulphur content of the clinker increased in proportion with the amount of sulphur in the fuel. Reactivity of clinker also depends on the nature of sulphate bearing phase. The higher sulphur present in the clinker causes fine clinkerization, alite and belite grain size and changing the reactivity.

Higher amount of alkalis (Na2O & K2O), coming from the use of alternative raw materials and fuel during the production of Portland clinker, led to the formation of orthorhombic polymorphic form of C3A instead of cubic (detected by XRD), leading to the different reactivity and hydration characteristics. C3Aorthorhombic is more reactive results in shortening in setting time, problem in reactivity and difficulty in controlling rheology. C3Acubic/ C3A orthorhombic influences the water consumption of the cement and higher water consumption by C3A orthorhombic.

Microscopic evaluation of Portland clinker is another way to investigate quality of clinker, and cement properties by analysing the morphology (mineralogy as well as granulometry) of clinker and interpreting the OM images as given below in Table 4. Images of major grains observed in Optical microscopy are shown in Fig 4. Optical micrographs of some clinker samples are given in Fig 5.

Table 4: Microscopic images and their influence

Observations in OM images

Interpretations

Increase in alite size and content

Relative high LSF, long sintering zone, coarsening of feed

Inhomogeneity of clinker phases

Lower reactivity of ash, short retention time, heterogeneity of raw mix

Highly porous clinker

Sandy raw meal

Cannibalistic or fused alite

Reduced reactivity of clinker

Inclusion of belite in alite grains

Reducing conditions

Large variations in alite size

Inhomogeneous raw mix

Small alite grains

Short flame, fast heating rate, shorter burning zone

Decomposition of alite

Slow cooling, reducing conditions

Large proportions of belite

Low LSF

Belite nest

Ash shortage, excessive quartz grain size

Large number of belite clusters

Decreased grindability

Large belite

Overheating or overburning

Coarsening of belite, aluminate, ferrite

Slowly cooled clinker

Ragged margins of belite

Also due to very slow cooling

Rounded belite without lamellae

Rapid cooled clinker

Secondary belite on alite grains

Slow cooling

Irregular belite

Over burning

Coarsely crystalline liquid phase

Slow cooliong

Therefore, quantitative estimation of clinker phases through microscopy and XRD is very important in controlling and monitoring the quality of raw material as well as clinker. Monitoring and identifying mineral and morphological features can effectively control the process conditions.

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Process

Price hikes, drop in input costs help cement industry to post positive margins: Care Ratings

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Region-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

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Wonder Cement shows journey of cement with new campaign

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The 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.

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In spite of company’s optimism, demand weakness in cement is seen in the 4% y-o-y drop in sales volume. (Reuters)

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Cost 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
Premiumization of acquired brands, synergistic?operations hold promise for future profit growth Topics

UltraTech Cement
India’s largest cement producer UltraTech Cement Ltd turned out a bittersweet show in the December quarter. A sharp drop in fuel costs and higher realizations helped drive profit growth. But the inherent demand weakness was evident in the sales volumes drop during the quarter.

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
What also impressed analysts is the nimble-footed integration of the recently merged cement assets of Nathdwara and Century, which was a concern on the Street.

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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