Displaying items by tag: Slag

Ukraine: Germany’s HeidelbergCement is selling its assets according to sources quoted by Interfax-Ukraine. It is reportedly selling to local investment group Concorde Capital and the deal will be completed during March and April 2019. The building materials local subsidiary, HeidelbergCement Ukraine, has not commented on story. The company operates integrated plants at Kryvyi Rih and Amvrosiyivka and a slag grinding plant at Kamyanske. Its loss rose by 14.4% year-on-year to around Euro14m in 2017.

France: Hoffmann Green Cement Technologies has inaugurated its pilot plant at Bournezeau, Vendée. The 50,000t/yr unit will manufacture cement products using metakaolin and blast-furnace slag, according to the L'Usine Nouvelle magazine. It says it will produce cement with reduced CO₂ emissions up to 250kg/t using a flash-calcined process down from 900kg/t in the normal clinker production process. The project had investment of Euro10m.

India: Jindal Steel & Power (JSP) plans to build a 2Mt/yr slag cement plant at Angul in Odisha. The US$68m unit will use ground granulated blast furnace slag sourced from a nearby steel plant operated by JSP, according to the Business Standard newspaper. A recent expansion at the steel plant to 6Mt/yr has allowed it to support a cement plant of this size. Land for the project has been acquired and the company hopes to obtain it from the state government by early 2019.

India: A joint-venture project involving the Steel Authority of India (SAIL) to build a new cement plant at Sundargarh in Odisha has stalled. Following support by local politicians for the plans in February 2017 no further action has been taken, according to the New Indian Express newspaper. SAIL originally made plans in 2006 to use blast furnace slag from the Rourkela Steel Plant and fly ash of NTPC-SAIL Power Company for the unit. It also intended pick up the lease for a limestone mine at Purunapani. However, it later ran into troubles securing state agreement to use the mine.

France: Hoffmann Green Cement Technologies’ pilot plant at Bournezeau, Vendée is set to start commercial production of low-carbon cement products in January 2019. Construction of the 50,000t/yr unit is due to be completed in October 2018 with its inauguration scheduled for late November 2018, according to Batiactu. The plant will employ 10 workers initially and this will rise to 15 – 20 as production ramps up.

The producer intends to make cement products using metakaolin and blast-furnace slag. If the pilot plant is a success it then intends to raise funds to build a 0.5Mt/yr plant.

Italy: Cemitaly has been allowed to use slag and ash in cement production at its Taranto plant following an investigation, according to the Il Fatto Quotidiano newspaper. The former Cementir unit was investigated in 2017 as part of an illegal waste probe that examined whether the Taranto plant purchased ‘illegal’ by-products from Enel and the ILVA steel plant to produce cement.

There is lots to mull over for the cement industry from last week’s Global Slag Conference that took place in Prague.

One striking map from Michael Connolly, TMS International, showed the status of slag and steel products in the US. It was a multi-coloured patchwork of different regulatory statuses from approval to be used as a product to regulatory exclusion. This won’t come as a surprise to many readers but even within one country the way slag can be used legally varies.

As this column reported last year after the Euroslag Conference, the European Union can be presented in a similar way. The irony here is that increased use of slag and other secondary cementitious materials (SCM) is exactly the kind of change the cement and concrete industries need to make to decrease their carbon emissions. Constant quibbles over whether slag is a product or a waste undermine this. Happily then that Connolly was able to report progress in the US as lobbying by industry and the US National Slag Association have led to more states legally accepting slag as a product.

However, cement producers have other concerns in addition to environmental ones when it comes to slag usage as Doug Haynes from Smithers Apex explained. Haynes, a former UK steel industry worker turned consultant, spoke around a market report on the future of ferrous slag. His take on Basic Oxygen Furnace (BOF) slag was that despite fuel savings, decreased CO₂ emissions and the benefits of embodied iron when it is used as a raw material for clinker production, it is in the interests of cement producers for slag to be a waste because they then get it for free or at a reduced rate. It’s a similar story to the use of waste-derived fuels powering cement plant kilns where producers want lower fuel costs but waste collectors want value for their product. Unsurprisingly, Haynes wanted cement producers to accept the value embodied in BOF slag.

Charles Zeynel of ZAG International, an SCM trader, then laid out the situation where global SCM supplies are remaining static but cement demand is growing. Coal-fired power station closures are reducing supplies of fly ash, another SCM, placing pressure on existing granulated blast furnace slag (GBS) slag supplies. The message was very much in a slag trader’s favour but instructive nethertheless. If slag is in demand then the price will rise. Anecdotally, the increased number of cement producers at the conference seemed to indicate increased interest of the cement industry in the product.

Lots more speakers followed on topics such as slag beneficiation, grinding advances and new innovations. On grinding, one surprise that popped up was that Spain’s Cemengal has sold a Plug & Grind Vertical mill to CRH Tarmac’s cement plant at Dunbar in Scotland. It is the first such sale of this product in Europe. The last speaker, Jürgen Haunstetter of the German Aerospace Centre, stuck out particularly with his presentation on using slag as a thermal energy storage medium in a concentrated solar power (CSP) plant. This may not seem connected to the cement industry but it is along similar lines to Italcementi’s project at the Aït Baha cement plant in Morocco, which uses a CSP process that can be used with the plant’s waste heat recovery unit.

The Global Slag Conference will return in April 2019 in Aachen, Germany.

Read the full review of the 13th Global Slag Conference 2018

India: Wonder Cement has ordered two vertical mills from Germany’s Gebr. Pfeiffer for its Nardana plant in Rajasthan. The order includes a MVR 6000 C-6 mill for grinding slag cement and a MPS 3070 BK mill for grinding fuel. Delivery is scheduled for early 2019 and mid-2019 respectively.

The MVR mill will feature a total drive power of 5820kW. Mixed cements will be be ground to a fineness of up to 5% R 45µm. The grinding plant will be designed to process granulated blast-furnace slag with a target fineness of approximately 4500 cm²/g Blaine and blast-furnace cements with different proportions of granulated blast-furnace slag, fly ash and gypsum and different product fineness degree. Wonder Cement has requested the option to grind relatively hot clinker in the mill while at the same time being able to reduce the cement temperature, and alternatively to use cold clinker from stockpiles.

The core components such as the tension system and the grinding rollers will come from Gebr. Pfeiffer in Germany. The grinding bowl and the gearboxes for the mill and classifier will also be delivered from Europe. Gebr. Pfeiffer’s subsidiary, Gebr. Pfeiffer India, will provide the housing parts, the foundation parts and supports of the rollers as well as almost the entire high-efficiency classifier type SLS 5600 BC. Gebr. Pfeiffer India scope of supply will incorporate most of the equipment to complete the grinding plant including the plant fan.

The MPS mill will grind petcoke with a capacity of 40t/hr to a product fineness of 2% R 90µm. It will come with a SLS BK classifier, allowing both coal and petcoke to be ground in the mill, dried with process gases and then classified in the integrated classifier. Due to the high abrasiveness of Indian coal, the mill will be designed with appropriate wear protection.

Most components of the coal mill will be supplied by Gebr. Pfeiffer India. The housing and foundation parts, the grinding bowl and a large part of the power-transmitting parts will be manufactured in India. Setting up the new MPS mill is planned to coincide with the commissioning of the entire kin line.

Australia: The New South Wales Environment Protection Authority (EPA) has fined Port Kembla Milling’s cement and slag grinding plant US$23,000 for allegedly storing raw materials in the open, in breach of its licence conditions. Raw materials, including gypsum and limestone, were allegedly stored in the open at the subsidiary of Cement Australia on at least five occasions since January 2016 in breach of the site’s planning approval and licence conditions. Such materials should be stored in an enclosed location to prevent dust emissions.

“The requirement to store materials in an enclosed building is a key way to ensure dust emissions from bulk materials are prevented. A measure that is very important given the residential areas near Port Kembla port,” said EPA Regional Director Metropolitan Giselle Howard.

In addition to the fines, the EPA has also required Port Kembla Milling to complete an independent raw materials handling audit to confirm appropriate storage and management systems are put in place. The company has made some initial steps to respond to this request, and the EPA will continue to work with the licensee to ensure full compliance.

Putting two speakers from the European Commission front and centre at the start of this year’s European Slag Association Conference (EuroSlag) in Metz, France was always going to cause a ruck. Once Coal and Steel Research Unit head Hervé Martin and steel sector policy officer Gabriele Morgante said their pieces and the panel opened up then the verbal punches started flying. Okay, this may be slightly exaggerated, but after a bunch of policy-heavy presentations, suddenly the situation became crystal clear. Was the agricultural use of ferrous slag going to be allowed to continue? What would be the classification of the slag? And so on. One Russian delegate commented afterwards, “I thought we had environmental problems in Russia.”

Jérémie Domas, Centre Technique et de Promotion des Laitiers Sidérurgiques (CTPL) explained in a later presentation that the heart of the current debate goes back to the European Waste Framework Directive (2008/98/EC). This legislation created an ambiguity over the status of slag between classifying it, as a waste or as a by-product, that the European industry has been battling over ever since. A multi-coloured map in Aurelio Braconi of the European Steel Association’s (Eurofer) presentation depicted the disarray this has caused with the varied legal statuses of slag across Europe. To add to this, Braconi’s home country of Italy, for example, is split into designating slag as both a product and a waste. His response was to say that the ‘human factor’ was important back home for utilising slag. The European Union (EU) is now working on its Circular Economy Package, which includes revised legislative proposals on waste, and it has been consulting on various issues throughout the year. It is this process is that been making slag producers twitchy.

Other delegates on the first session’s panel provided a bit more context, with Thomas Reiche of the German Technical Association for Ferrous Slag (FEHS) saying that the waste legislation didn’t need to be changed but that public procurement laws did. Eric Seitz of the French Association of the Users of industrial By-products (AFOCO) added that slag products had been sold for decades without any problems. However, he definitely wanted ‘strong’ support from the EU on the issue.

Moving on, Craig Heidrich of the Australasian (Iron & Steel) Slag Association (ASA) provided some interesting figures in his presentation on worldwide slag production that differ from the data often reported by trading companies. Heidrich reckoned that 567Mt of slag was produced in 2015 with a breakdown of 347Mt blast furnace (BF) slag and 220Mt steel slag.

Andreas Ehrenberg of the FEHS presented research on converting electric arc furnace (EAF) slag into a hydraulic material that could be used in cement or concrete production. Given that, using Heidrich’s figures for example, about a third of ferrous slag production is steel slag often created in an EAF, the potential implications of this line of inquiry are important. Unfortunately, the main disadvantages of the original EAF slag analysed in Ehrenberg’s work compared to BF slag are the lower CaO and SiO₂ contents and the higher MgO and Fe oxide contents. Laboratory-scale tests confirmed in principle the feasibility of forming clinker or ground blast furnace slag-like materials based on EAF slag. But the reduction and treatment steps in the process require a lot of effort and the economical value of the recovered metal is low. Taking the research further will require much more work on the semi-technical scale.

The other paper with particular relevance to the cement industry was Chris Poling of SCB International unveiling his company’s ground blast furnace slag (GBFS) micro-grinding mill, the Nutek Mill 2. The new mill is intended to allow slag grinding to take place in a much wider range of locations, along similar lines to the modular clinker grinding mills made by Cemengal or Gebr. Pfeiffer’s Ready2Grind line. The pilot project is being installed now in New York State, US. The mill has a GBFS capacity of 10 - 12t/hr with a target of 40 – 45kWh/t when fully optimised. Further units at the same location are planned for early 2018 with approval sought from the New York State Department of Transportation.

The 10th European Slag Conference is expected to take place in 2019. With more clarity expected from the EU on its Circular Economy Package there will be much to discuss.