Oman Cement Company (OCC) was established in 1977 to produce cement for the development of Oman. Located near the capital Muscat, the company’s cement plant was commissioned in 1983 with a single 2000t/day Polysius line. Following the addition of further production lines in 1997 and 2011 and an upgrade to the original line in 2014, the plant now boasts 9000t/day (~2.7Mt/yr) of cement production capacity. Global Cement recently visited the plant, spoke with key members of staff and saw how the plant is equipping itself for the years to come.
Production and process
Global Cement (GC): Can you describe the production process as used at the plant today?
Hamdan Salim Al-Hussaini – Head of production: Crushers (HSAH): The limestone that we use comes from our captive quarry, which is directly adjacent to the plant. It has reserves for at least another 50 years of operation. After blasting, it is trucked to the crushing section, where it is reduced first from a diameter of around 1m to less than 30mm.
There are actually three limestone crushers. One is a 650t/hr hammer crusher from Polysius and dates from the installation of line one. The second is a 1997-vintage mobile crusher with a capacity of 800t/hr. It was built by Japan's IHI and came online with the second line, which was also from IHI. The third crusher arrived in 2013. It is a 1200t/day Titan crusher that supplies to the Polysius line, the IHI line and line three, which was installed by Sinoma in 2011. During normal operation it is the only crusher that we use, but we revert to the first two crushers when it is halted for maintenance.
From the limestone crushing section, the material heads to one of three 40,000t homogenising storage domes, which means we have 120,000t of limestone storage in total. These were built by Sinoma in 2013.
GC: Where are additives sourced and how are they processed onsite?
HSAH: All of our additives are sourced from within Oman. Silica is obtained from a nearby quartz phyllite source, around 3km away. Iron ore is sourced from the same area. Our alumina source is kaolin from around 600km away. We used to import bauxite from India for our alumina but since we switched to Omani kaolin we proudly produce cement that has 100% Omani raw materials.
There are two additive crushing lines. The first dates from the first line and consists of a Polysius jaw crusher, a secondary crusher and a tertiary crusher. The first takes material of up to 400mm in diameter down to 50 - 70mm. The second takes it down to less than 25mm. If the material is less than 25mm it heads to our six 15,000t covered linear additive mix-beds. Any oversized material is diverted to the tertiary crusher to reduce it to below 25mm in diameter.
The second additive crushing line is a Metso installation from 2013. It has a primary 400t/hr crusher that takes the <400mm diameter material down to 50 - 70mm in diameter. A secondary crusher then reduces it to <25mm. On the Metso system, oversize material is looped back round to pass through the secondary crusher again before it heads to the mix bed.
The gypsum that we use is natural gypsum from Oman. It comes from a site that is owned by OCC. Material is extracted by a third party and is trucked to the plant.
GC: What about the raw mills and kilns?
HSAH: The limestone and additives are taken from their respective mix beds and are dosed into one of our five raw mills, all of which are ball mills. Raw mills 1 and 2 were established in 1981 with Line 1. In 2014 we upgraded these from 90t/hr combined to 120t/hr as part of a CNBM China project to optimise Line 1. Line 2 is fed by raw mill number 3 and has a capacity of 160t/hr. Line 3 is served by two raw mills, 4 and 5, which each have a capacity of 180t/hr. From the mills, the material is fed directly to one of the three kilns.
Abdullah Barashidy – Head of kiln section (AB): As for the kilns, Line 1 has a capacity of 2700t/hr, Line 2 is 2000t/day and Line 3 is 4000t/day. In 2014 we completed a major upgrade on Line 1, which was increased from 2000t/day to 2700t/day. Starting in March 2014 we changed the kiln, increasing the diameter from 3.8m to 4.2m. As well as the extra raw mill capacity, we installed a new clinker cooler in collaboration with IKN in Germany. CNBM China changed some cyclones and flash burners. It also increased the number of stages in the pre-heater from four to five. Presently, Line 1 is operating at 2700t/hr. At an earlier stage the project also included a switch from electrostatic precipitators on Line 1 to a baghouse from China's SEPEC. Later in 2015, by the year end, we are expecting to conduct a similar upgrade on Line 2.
Line 3 has produced 4000t/day since it was commissioned in 2011. The plant has a potential of greater than 5000t/day and there is a plan to upgrade it further.
GC: Was the commissioning of the revamped Line 1 smooth?
AB: Commissioning was generally smooth and was carried out by OCC operators under the supervision of representatives from CNBM China. Inevitably there were some small problems because it is always more difficult to modify an old line than start a new one.
For example we now have two ID fans instead of one, which affects a lot of process parameters.
GC: You mentioned that part of the Line 1 project was a new IKN cooler. What coolers are used on the other two lines?
AB: All of the coolers are from IKN. Indeed, the decision to install an IKN cooler on Line 1 stemmed from our previous positive experiences.
GC: Can you take us through the plant's clinker storage and grinding equipment?
Abdullah Saif Al Siyabi – Assistant Head of Cement Mill Section (ASAS): Certainly. There are four clinker silos; two 30,000t silos dedicated to Line 1; a 30,000t silo for Line 2; and a big 56,000t silo for Line 3. We have four cement ball mills at present. Two are Polysius installations from Line 1, each with a capacity of 62t/hr. With Line 2 came cement mill 3, which has a capacity of 70t/hr. It is from IHI. Since we had high demand, in 2006 L&T India installed cement mill 4, which has a capacity of 150t/hr. At the moment we actually run some of the mills slightly above their rated capacities. Mills 1 and 2 operate at around 70t/hr and mill four runs at 165t/hr. Mill five is currently under construction by FLSmidth India and will be completed by October 2015.
AB: After the mills there are eight cement silos in all. Six have a capacity of 5000t each and were installed at the start of the plant. A seventh 9000t silo was installed with the second line and the eighth is a 1500t silo dedicated to oil well cement.
HSAH: There will be two new cement silos to accommodate the extra capacity coming from cement mill 5 once that is complete.
GC: What types of cement are produced here?
AB: OCC makes Ordinary Portland Cement (OPC), sulphate-resistant cement (SRC) and oil well cement (OWC). We make about 10,000t/month of OWC clinker, which is primarily ground on cement mill 3. We selected mill three because it has a second-generation separator that allows the right quality and particle size distribution. The remainder of the output is OPC and SRC.
GC: The plant has components from many different suppliers. What problems does this cause?
ASAS: This can be challenging as we have to have a high inventory for the different parts of the plant. That said, we have standardised some parts. For example mills four and five are from different suppliers but their gearboxes are both from MAAG Gear, which is now part of FLSmidth. We also have all ball mills and a lot of the components are common for those.
Controls and maintenance
GC: What control systems are in place?
Sabir Hilal Al Rahby – Production Information Technician (SHAR): Since July 2012 we have been using a SAP system that was installed by L&T India to monitor production and the entire plant process. It has been a vast improvement on the previous AS400 system because it has increased the availability of information between our different departments.
It works with ABB's Knowledge Manager system, which takes data from each weighing device within the plant. We have been able to increase the level of our process knowledge. The resolution of our data is now higher and we can now monitor any process problems in real time, rather than analysing them after the event. Managers can even access the data from their homes, the airport or abroad, which is good and bad – we can't switch off!
GC: What can you tell us about the production and shutdown regimes here?
HSAH: When they are running, the three lines operate at more or less their rated capacity. That said, we obviously have a production and maintenance plan, in which we list all of the major projects and shut-down periods for the year. We shut each line and its associated mills for maintenance twice a year at different times, so we never stop making cement. However, the cement mills get no rest! When we have cement mill 5 we will have more grinding capacity than clinker capacity, so this may change going forward.
In Oman we have to produce cement all through the year because demand is not seasonal like in some other parts of the world. The only reduction in cement sales that we see is related to Ramadan, when work on construction projects is less intense.
Fuels
GC: What fuels are used by the plant?
AB: We use natural gas for the kiln and the pre-calciner. This is supplied by the government at a favourable rate. However, the rate has almost doubled since the start of January 2015 from US$1.50/mmbtu to US$3.00/mmBtu. Due to this situation we are increasingly looking at alternative fuels and have undertaken some initial discussions with regional partners about the use of tyres. We want to burn these whole in the pre-heater but are not able to say when this might start.
There was also a proposal to use Omani coal, which was discovered in 2014. However, it is not government strategy to use this at present. Of course, if we switched to coal, we would have to install coal mills and make changes to the burners on each line.
ASAS: Of course, as well as the economic concerns we want to continue our environmental record going forward. We are always working so that we are ahead of government requirements and are considered a good neighbour by those living and working near the plant. However, there are challenges, for example the government is constantly wanting us to expand production. We have to factor our new alternative fuels into that situation.
GC: Does the plant use or have any plans to use alternative raw materials?
HSAH: We don't use these much at the moment but we are conducting some trials. At the moment we receive a waste product from the oil refining industry by truck twice per week. This is actually mixed with the limestone in the crusher. We are also conducting trials with waste bricks from demolition sites. We have only had one delivery to date so we are very early on in the trial.
Quality control and testing
GC: What quality controls are in place to ensure that the cement meets standards? Does this happen in house?
Abdul Mazhar Baig – Quality Control Manager (AMB): The plant has a thorough quality control process that operates from our chemical and physical labs. We take samples of all of the raw materials, clinker, cement and gypsum automatically via an ABB system, grind it and press it into a tablet. We then analyse the materials using one of our X-ray fluorescence analysers. The information about the compositions is fed back into the system, which will then automatically adjust the amount of each raw material entering the raw mill. We also conduct the normal range of physical tests, including strength development and water absorbtion.
The facilities have been certified by the Ministry of Commerce & Industry but we are currently applying for ISO17025 accreditation. When this is granted, we will be able to receive cement samples from all over the world, which is a small revenue stream and a potential source of knowledge. This will apply to OPC, SRC and Class A and Class G OWC.
Corporate social responsibility
GC: How does the OCC Corporate Social Responsibility (CSR) department interact with local stakeholders?
Nadar Faraj – Head of Corporate Social Responsibility (NF): OCC has been involved in social responsibility for many years but each department was working independently. In 2014 we put these under the banner of a new CSR department, which brought all of those activities together. In 2014-2015 we dedicated 1% of net profit to CSR and in the forthcoming financial year we will dedicate 2%. That means in 2014 - 2015 CSR had a budget of around US$400,000.
The CSR department is about giving society back what we take from it. Between us, the Ministry of Social Affairs and the NGOs we budget the money to projects that will provide the most benefit to the most people.
We are involved, for example, in projects to supply books and other school equipment, school meals and uniforms to less fortunate school children. We also donate free cement on a small scale, subject to local need.
These might sound like charity projects but the Koran says that if someone is in need, part of your money is rightfully theirs. The money is theirs, so it is not OCC’s to ‘give.’
Another part of CSR is the formation of joint-ventures between the plant and local committees. This way OCC can benefit from the service that joint-venture provides but part of the control and the profit of that operation is in the hands of the local workers.
As head of CSR I am also responsible for external-facing communication with the plant. We communicate with locals through local media and direct meetings. This helps us identify issues that need to be raised within the plant management.
Markets and the future
GC: What is the plant's natural market and how is material delivered to it?
Hilal Saif Al-Dhamri - Senior Production Manager (HSAD): OCC primarily supplies the north of Oman, including the area around Muscat and the interior. We supply major government infrastructure projects, including roads, hospitals, home-building projects and a major new airport terminal at Muscat International Airport. More widely, we supply the northern 'half' of Oman. Raysut Cement covers the
southern market.
We do not have a distribution network of our own so the customer drives its truck to OCC and purchases the cement directly at US$60/t (bulk). There is a 50:50 split between bagged and bulk cement. We use a Haver & Boecker RotoPacker system to pack bags from Mondi. The Mondi plant, in which OCC has a 30% stake, is located only a few kilometers from here.
While our API Monogram Certified OWC is exported via agencies to Kuwait, Pakistan, Yemen and Iraq, we do not export our OPC or SRC. This is because our company was established first and foremost to support the development of Oman. It remains 51% government-owned.
GC: Are cement imports, specifically from the UAE, a threat to OCC?
Salem Abdullah Al-Hajry – Deputy CEO (SAAH): Demand for cement in the Omani market is higher than the production capacity of domestic producers. Cement imports from the UAE and elsewhere are therefore necessary and will continue unless there is a drastic increase in domestic capacity. We sometimes import clinker to make-up supply in case of shutdowns of our kilns.
In the longer term we are aiming to increase production at OCC but it will not be enough to replace imports, as around 40% of the cement used in Oman is imported.
At the moment the situation with imported cement is stable but sometimes we lose out on price. However, in the past few weeks there has been an increased demand at the plant which was far above our capacity. We think this is due to the authorities clamping down on overloaded trucks. This means that more trucks are needed to transport the same amount of cement as before. Under those circumstances a long drive to the UAE becomes less attractive.
GC: What are your longer-term expectations for the Omani cement industry?
SAAH: We may see a strong demand for cement and growth in the Omani cement industry. However, the government's recent decision to double the price of gas fuel, which we use for kiln firing, represents a great challenge to us as far as production cost is concerned.
Going forward, increasing prices will be the last option for us as our primary concern is to provide cement for Oman at a reasonable price. We can profoundly make great strides in power reduction, electrical efficiency and other areas like alternative fuels before we increase our prices.
Looking a bit further into the future, I expect that cement production will double in the coming five to 10 years. There is large development activity in Oman, in particular in the Duqm region. The area is going to grow fast with ports, new roads, industries, hotels and other tourist developments.
As far as domestic cement production is concerned, we are exploring the possibility of a joint-venture cement plant with Raysut Cement at Duqm. There may even be other producers looking to invest in the region, although there are potential stumbling blocks around the supply of raw materials.
GC: What one thing would you change overnight about the plant if you could?
SAAH: A working culture in which our team becomes more effective on handling the challenges of cement plants in a proactive manner. Part of this involves the inclusion of all staff, especially our many young Omanis, who will be the future of this operation.
GC: Thank you all for hosting our visit today.
SAAH: You are very welcome indeed.
