Stories by Maduka Nweke
Razaq Babatunde Lawal, Chief Engineer, Pozzolana Pilot Plant at Nigerian Building and Road Research Institute (NBRRI) is a Metallurgical Engineer and member of the Nigerian Society of Engineers (NSE) as well as a registered member of Council for the Regulation of Engineering in Nigeria (COREN). After working at Ajaokuta Steel Company Limited in Kogi State, Lawal garnered other experiences including metal recovery smelter plant experience, worked at Metropolitan Batteries Ltd in Ogun State and Associated Battery Manufacturing (ABM), Lagos.
He later joined the Federal Government-established research institute, the NBRRI, where he rose to the rank of Manager, Pozzolana Pilot Plant in the institute.
In this interview with Daily Sun, Lawal fielded questions on issues bordering on building materials and why their costs have continued to soar despite efforts by local manufacturers to lower prices.
He noted that if government should give Pozzolana products attention encourage more Nigerians to patronise locally produced building materials, its over-dependence on importation would reduce. He added that if the various raw materials in the country are processed and harnessed, Nigeria will have no reason to import building materials.
About Pozzolana Pilot Plant
We call it pilot because it is still in a small scale operation. The output is only two tonnes so we could make it commercial by increasing the capacity to 20 tonnes to 30 tonnes. This was developed for the investors to take up and the government will be interested to carry it to the next level.
Meaning and role of NBRRI
First, it is the Nigerian Building and Road Research Institute. Every country must have an institution, a research arm and without research, we will continue to import virtually everything into the country. Nigeria has more than 35 research institutes and this is one of them. Our major mandate at NBRRI is to conduct applied research into roads and building materials for the construction sector. It was established in 1978 and we have been carrying on research in this area. This aspect of the institute, the Pozzolana Pilot Plant, that was recently commissioned is a way of assisting the construction industry to have an alternative material, which will complement existing building materials. The name came from Italy, a place called Pozzuli. So Pozzolana is an alternative material. It is a composite material of clay added to cement to enhance the quality of the cement in terms of workability, reducing heat of hydration but can still have higher strength in latter days, higher curing days. So instead of curing at 28 days, it gets its maximum strength at 40, 60 days. But with the components of Pozzolana, which are basic alumina, silica and iron oxide, it will react with the free oxide, free lime in cement to form the calcium silicate or alumina compounds that are the major components of cement.
Importing building materials
In fact, importing building materials from abroad should gradually stop and we should empower the local research institutes and university students to take up such projects of plant and equipment designs to produce and we should patronise them. Like this product that was commissioned recently, we expect investors to come in, to know about it and scale it up to higher commercial volume. It is possible to have a building that is started and finished with materials that are locally sourced. For example, this is concrete but we are using the conventional Dangote cement but in future, we can use Pozzolana in concretes and mortar.
Localisation of process
One thing about Pozzolana is that it is a generic name so we cannot change the name to Ota or another thing, probably where the clay is obtained; it will lose its international meaning. All architects, civil engineers and students of architecture know Pozzolana; so any attempt to change or localise the name will make it no longer international. The whole idea is that we are borrowing from that. When we went to Ghana, we collaborated with Council for Science and Industrial Research, Building and Road Statistics of Ghana. That is where we went to bring this product here. Ghana calls it Pozzolana too. So it is not only Nigeria because the product is international and that is why we still maintain the name Pozzolana cement extender.
Products manufactured here
We manufacture bricks (block); the sizes are bigger than the smaller clay bricks. These blocks were used in building this factory. It is a selection from laterite soil. We stabilise the laterite to give it strength and then it is cured, after curing it, it becomes strong. The beauty of it again is that we don’t use mortar to join individual blocks, we just interlock it. So we produce interlocking blocks for housing. Now we are producing Pozzolana for mortar and concrete and other researches that are not in hard copy but in software, namely, geotechnical studies. This year, we just launched the Atlas of sub-grade soil in the country. This will be useful in planning road routes so as to avoid premature failures of roads. So, there are many researches that are just on paper, these are the outcome of the institutes’ researches. But this is the first pilot plant that we have started based on this product.
Nigeria’s potential to supply its building material needs
Sure, for example, Ogun State alone, not to mention other states like Anambra and Kaduna, is vast with clay. In fact, this is my first time of seeing this type of clay from Yewa, a black clay. This quality of clay is known when you put water on it, you will observe the clear nature of it. We have red clay in Ipokia, we have it around the Imoto-yewa. So once a clay is composed of silica, alumina and iron greater than or equal to 75 per cent, it is qualified to be called Pozzolana.
Other building materials manufactured here
We have the ceramics department that supposes to produce ceramics. So we have samples of ceramics. It will pass through the “biscuit state” and it will be fired to produce ceramics. But like I have said earlier, our products are at the research level that we want investors to come around and make it to the industrial/commercial point.
Roles of these machines
As you can see, we have the hammer mill, it hammers and there are five sets of hammers, three, and four in a line in about four rows making 20. So when you throw in these hard materials, the hammers will hammer them and ground them to small particulate size. So there are three hammer mills. We also have the palm kennel shell like the machine. Initially, when we brought in the hammer mill, we thought it can grind the palm kennel shell but the palm kennel is harder and fibrous. It was just breaking it so we had to get some fabricated ones indigenous to Nigeria. So this machine grinds it into very fine powder. Palm kennel is the source of our fuel, so it is mixed with our clay, which is brought and taken to the other machine, which we call noduliser because we are bringing two powdry materials with addition of water to be able to get it to small sizes which we call nodules. In these nodules, we have green strength and with this green strength, when you fire it in the Vertical Shaft Kiln (VSK), it now becomes very hard. You now take it out and grind it further in the Ball Mill to form very fine powder that can be very reactive to cement to be used with cement products, to produce mortar and concrete.
There is the VSK. You will be surprised that out of all the machines, this was locally fabricated and it was designed in-house aside most of our other machines that are imported. It is such a situation in engineering. We can design some of the machines because we have devoted so much time studying plant and equipment designs. The basic thing in VSK is the height to diameter ratio of the barrel. I have designed other machines like rotary furnace. So this is called VSK, so when I brought out the information some years back, the Chemist in charge of this Section called me and we eventually came up with this idea of designing a VSK, and as God will have it, it came to fruition while I am still in the institute. The overall height is 8.5 meters while the diameter is 2.2 meters.
The Cup Elevator is imported. When I told the Chinese the height o mine equipment, he gave me the hopper of 10 meters. Then I arranged the cups and did all the assembly. Everything in terms of the plant, I did it and then the only thing we brought on the kiln area is the blower fan. That blower is the powerful fan that supplies forced air to the kiln and the air is used to preheat the kiln. The Palm Kennel Shell (PKS) within the nodules provide the generating heat inside the materials. So when you heat, it dries it as it is in contact with the clay so that it can dry very well.
Challenges in manufacturing local building materials
There are a lot of challenges we face as manufacturers and that has to do majorly with energy. Yes, energy is very important in any manufacturing industry. You know there is epileptic power supply; like now, we are using generator to power the machines. There are a lot of machines here we cannot use because the energy to power them is not adequate. So if government can make energy available, it will assist those in the manufacturing industry and those using heavy power equipment to get on. As you can see, these machines should be powered by high energy supply, otherwise they will only break down and they will not give you what you want. If a Small or Medium Enterprise (SME) has a small harmer mill, one noduliser and a local VSK not as high as this and a small Ball Mill, he can make his own Pozzolana. So this is what we call “blended cement”. When you mix Pozzolana in the ratio of 40 per cent, you will get the same outcome in performance and quality of material you can produce from cement.
Percentage of imported building materials
With the increase in the capacity installations at Dangote Cement and Larfarge, importation of cement has reduced drastically. I have graphical data from Dangote and Larfarge about production but Nigeria is still the least compared to African countries. Our production is much less than what we use but with the likes of Dangote, I think we are gradually going to reduce the gap. This is why I said manufacturing industries should have their own gas turbines to supply their own electricity. Even universities like, Covenant University have installed gas turbine for power generation.
This is done in developed countries. Dangote and other big manufacturing companies should have their own turbines so that nothing will disrupt their production process. Again, excess power from such plants should be exported to the national grid so that we can have enough power. In fact, power is very important to the growth of the country’s economy. I think government should do enough to get us more power.