Archive for cements
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Here’s what we are hearing:
In the cement industry, the ball mill is probably the nemesis of all staffs. Why? Everybody knows that a cement mill is a technological heresy on an energetic point of view. The mill’s efficiency is extremely poor and the work to get some improvement is huge! We hope this site will give a little help for those who spend a large part of their lives for their ball mill. In this site, you will find some tools, such as calculators for volume load power, cement mill-2 compartments power, cement mill-3 compartments power, monochamber mill power, raw mill power, birotator central discharge mill power, ball charge make-up, Tromp curve, RRB Curve, drying capacities and heat balance.
(GigaOm) As early as this summer, Solar Mosaic plans to start offering people a way to buy into rooftop solar panel projects, and make back a return on their investment over time. Essentially for the investor it will be like buying the safe and predictable return of a mutual fund. The way it works is that a building owner will lease the solar equipment and enter into a contract for a fixed, low, electricity rate, commonly over about two decades. Solar Mosaic is working with solar lease providers like Sungevity, but Solar Mosaic is the one that organizes the crowd-funding of the money to get the solar rooftop installed. Once the project gets funded Kickstart-style, the rooftop solar panel installation process starts. Solar rooftops are a surprisingly low risk investment. As Daniel Rosen, cofounder of Solar Mosaic put it in an article for us last month: solar loans are backed by a revenue-producing asset (electricity) and the building owners are just continuing to pay for the electricity that they are used to paying for day in and day out. There is little risk to investors that the buildings owners will default on their electricity payments, particularly since they are also saving money on their energy bills from day one. In addition the costs, timelines and returns for solar panels are pretty transparent as the technology has become increasingly commoditized.
Westinghouse Electric Company and the Missouri Electric Alliance led by Ameren Missouri announced the formation of a utility participation group called the NexStart SMR Alliance. The Alliance is a consortium of current and prospective nuclear plant owners and operators and includes cooperative, municipal and investor-owned electric service providers, as well as public enterprises to advance energy security. Alliance members signed a Memorandum of Understanding that recognizes the importance of advancing nuclear energy in helping secure clean, safe and reliable electricity in the future by deploying the Westinghouse Small Modular Reactor. The initial membership of the NexStart SMR Alliance includes Ameren Missouri, Exelon Generation Company, Dominion Virginia Power, FirstEnergy Generation, Tampa Electric Company, Arkansas Electric Cooperative Corporation, Savannah River National Laboratory, and members of the Missouri Alliance: Missouri Public Utility Alliance; Associated Electric Cooperative, Inc.; Association of Missouri Electric Cooperatives, Inc.; The Empire District Electric Company; and Kansas City Power and Light Company. Westinghouse and Alliance members are also in discussions with other utilities and enterprises considering NexStart SMR Alliance membership in order to support the potential deployment of a Westinghouse SMR at Ameren’s Callaway Energy Center in central Missouri.
Architectural coatings protect and beautify buildings, but use tremendous amounts of petroleum, water and energy. Environmental imperatives mean that sustainability of architectural coatings is increasingly vital, and their role in building energy efficiency is growing with the widespread acceptance of building standards such as LEED and NZEB, according to a Lux Research report. Lux defines sustainability along three dimensions - environmental impact, energy efficiency and resource efficiency - to create a simple “Sustainability Value.” Comparing this metric with “Technical Value,” Lux Analysts mapped out the technologies that will impact the architectural coatings market. “Sustainable coatings technologies reduce the energy, resource, and environmental impact of paints and coatings, but often get confused with ‘greenwashed’ unsustainable alternatives,” says Aditya Ranade, Lux Research Analyst and lead author of the report titled, Painting a Green Future: Opportunities in Sustainable Architectural Coatings.
Ceramic Fuel Cells Ltd. announced its products have achieved a combined one million hours of operation. The company’s first field trial units were operated in Australia, New Zealand and Germany from early 2006. In 2007, the company developed its high-efficiency Gennex fuel cell module, which is the core of the company’s BlueGen product and integrated mCHP products. Up to May 1, 189 units have been operated at Ceramic Fuel Cells’ facilities in Melbourne and Germany, as well as at customer sites in nine countries. Brendan Dow, managing director, said milestones such as this are important. “These units are not just operating in our labs, but at many customer sites in nine countries around the world,” he says.
(MaterialsViews) Bayer MaterialScience plans to establish a global wind energy competence and development center at its existing site in Otterup, Denmark. The new competence center will spearhead and coordinate the global development activities for advanced materials used in wind energy applications. The plan for the center underlines the commitment of Bayer MaterialScience to develop innovative and sustainable materials and technologies for generating power from renewable sources. It will bundle the development capabilities from across the company’s entire portfolio of polyurethanes, polycarbonates as well as coatings, adhesives and specialties materials, pooling expertise from research and development teams around the world. While full details of the global wind energy competence center have yet to be decided, Bayer MaterialScience CEO Patrick Thomas sees it as an opportunity to deploy the company’s expertise in chemistry and processing to help achieve a sustainable reduction in the cost of generating energy from wind turbines.
(MaterialsViews) The Carl Zeiss AG Supervisory Board has elected Dieter Kurz as the new chair of its supervisory board, effective immediately. “With Kurz, we are gaining a chair who is very familiar with the company and the challenges of our portfolio through his many years of successful work as a member of the executive board and president and CEO of Carl Zeiss AG,” says Michael Kaschke, president and CEO of Carl Zeiss AG. “We at Carl Zeiss are looking forward to working with him.” Kurz was already appointed as chair of the shareholder council of the Carl Zeiss Foundation in March. According to the foundation’s constitution, this means that he is a member of the supervisory boards of the two foundation enterprises, Schott AG and Carl Zeiss AG, and is to be elected as chair by the two supervisory boards.
Representatives of leading international companies in the solar photovoltaic industry have announced the founding of the Global Solar Council, a CEO-level industry coalition whose aim is to expand the global deployment of solar energy in a sustainable and cost-competitive way. Global Solar Council members will engage with policymakers worldwide to demonstrate the progress towards abundant, affordable and low emissions energy already made possible by the solar industry and to emphasize the importance of a supportive policy and trade environment, which will enable the ongoing development of competitively-priced solar energy, driving job creation and economic growth. Through its members, the Global Solar Council brings industry knowledge and insights from all sides of the solar photovoltaic value chain; from the supply of materials to product manufacturing and financing, policy, research and innovation, cross-border cooperation, and grid development and management. Council founding members are Applied Materials, Dow Corning, DuPont Electronics & Communication, First Solar, Lanco Solar, Phoenix Solar and Suntech.
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Back in early January, I had a story about proposal from a Georgia Tech team of cements experts who had a remarkable pragmatic and inexpensive proposal for rebuilding Haiti: Recycle the concrete that is laying around in huge rubble mounds. (Their idea wasn’t to recycle it willy-nilly; instead they had proposed and tested some simple approaches using low-tech available tools and equipment to convert refuse into usable aggregate plus add some abundant local sands, which, together, could produce strong construction-grade concrete.)
I learned from one of the GT team members that the leader of the research effort, Reginald DesRoches, has recently secured funding from the non-profit Speedwell Foundation to support a new project, “Reducing seismic risks for developing countries in the Caribbean.”
Kim Kurtis tells me DesRoches’ goal is to assess whether “another Haiti” could occur. Kurtis, who like DesRoches is a member of the faculty at GT’s School of Civil and Environmental Engineering, says they already know there is a strong correlation among a country’s per capita GDP, fatalities sustained during an earthquake and overall economic losses. She says experience has demonstrated that countries with a lower GDP (e.g., Haiti, Indonesia) fare more poorly in the event of an earthquake than countries with higher GDPs.
In the Caribbean region, Kurtis notes, faults run not only through Haiti, but other populous islands, such as Jamaica. DesRoches’ initiative came about because, unfortunately, little has been done to assess these countries’ vulnerability in the event of an earthquake.
Kurtis, who again will be working with DesRoches, says the first year of research will involve touring the region and collecting data to better understand existing vulnerabilities (documenting hazards, construction quality, levels of preparedness, etc.). Phase I will culminate with a workshop, which is envisioned to include government officials, emergency managers, engineers and scientists—from the Caribbean and the United States—to discuss the findings.
Others involved in this project are Glenn Rix (also in GT’s School of CEE) plus three the university’s School of Industrial & Systems Engineering (ISyE): Ozlem Ergun, Pinar Keskinocak and Julie Swann.
Kurtis says the CEE members bring expertise in seismology, multi-hazard assessment,
structural behavior/design, cement-based materials and sustainability; the ISyE team brings expertise in humanitarian logistics (Ergun, Keskinocak and Swann also codirect Georgia Tech’s Center for Health and Humanitarian Logistics).
After Phase 1, it is likely that the group will turn its attention to converting their findings to practical solutions, such as enhancing building codes to improve seismic resistance in new construction, coordinating retrofit of existing structures using methods appropriate for the region and working with NGOs on both earthquake preparedness and short- and long-term responses.
At the recently concluded Advances in Cement-based Materials meeting organized by ACerS’ Cements Division and ACBM, Karen Scrivener of the Ecole Polytechnique Fédérale de Lausanne (Switzerland) was selected by the organizers to deliver the Della Roy Lecture. Scrivener is a highly respected expert in the field of cements and she was an appropriate pick, having followed in Della Roy’s footsteps as the editor of the Cement and Concrete Research journal.
Scrivener is also the founder of Nanocem, a Europe-based initiative working on collaborative approaches (not just among institutions, but also between institutions and industry) to cements questions. One of the aims of Nanocem is to spur a constant effort to reduce CO2 emissions:
“Evolving CO2 emission caps in Europe mean that cement manufacturers will have to find solutions, or pay more to produce cement, which will reduce their competitivity. Nanocem is sponsoring fundamental research that will support technological solutions, not only to help secure the long-term health of the European cement industry, but also to address global CO2 reduction by ensuring that cement manufacturing is not just shifted to regions of the world that have less stringent emissions regulations.”
The title of Scrivener’s Della Roy Lecture was “Modeling Hydration Kinetics of Cementitious Systems,” which was quite a good discussion about the what has and what’s yet to be done in the world of modeling cement microstructures.
But, as a non-expert in cements, I found Scrivener’s opening remarks, which provided the context for her technical presentation, a balanced and compelling discussion about the importance of cements and concrete to, well … the world!
A few of her salient points:
• Concrete is most used material in the world. It is the only material that can satisfy the demand for low-cost decent housing and infrastructure. There is no way to satisfy the demand for low-cost housing and infrastructure without concrete.
• The demand for concrete is growing and will continue to soar, especially in the developing nations. The demand may double or triple by 2050.
• Although cement production is energy intensive, the energy and CO2 emissions of concrete (per ton) is among the lowest of all building materials, even lower than wood.
• The CO2 problem associated with cements (5-8% of CO2 production world wide) is primarily because of the volume of demand.
• There has been talk of achieving 5-10% reduction in emissions per cubic meter of concrete through the use of substitutes for Portland cement. It may be more like 1-2% given the amounts and choices of supplements (see below), but even a 1% saving would be equal to removing all the CO2 emissions associated with steel production. “So that shows how much impact we can have by research to increase the sustainability of cement,” she said.
• The available elements in the earth’s crust imposes a fundamental limit on the options for substitute cementitious materials. Eight elements—oxygen, silicon, aluminum, iron, calcium, sodium, potassium, magnesium—make up 98 percent of earths crust. So, forget about making cement out of any other elements.
• The way this has been pursued over the last 20-some years is first of all process optimization. Cement kiln and other production operations have gotten much better and state-of-the-art plants are achieving 80% of their theoretical efficiency.
• So, recently the goal has shifted more to reducing the “clinker factor,” i.e., instead of grinding clinker and gypsum, add more and more supplementary cementitious materials. SCMs my be byproducts or waste products from other industries, such as limestone, fly ash, blast furnace slag, silica flume, natural pozzolans, etc.
• This has been a good and successful strategy (over the last 20 years 25% of the previous amount of clinker in cements is now substituted by SCMs).
• But … and this is a big “but” … this is going to be a difficult strategy going forward because under the best of circumstances, the amount of SCM available will be dwarfed by amount of cement produced.
• For example, people talk about using fly ash as an SCM and it is probably the most widely available. But, there simply isn’t enough fly ash worldwide to replace cement in any big amount. The availability of SCMs in underdeveloped countries, where the demand is going to be coming from, is small because by definition they don’t have the scale of industries to provide large volumes of slag and fly ash byproducts.
• So where are SCMs going to come from? More limestone, probably, but more calcined clays and natural pozzolans. Cuba may be a good source of calcined clays.
• There is no one single answer. All sustainability possibilities must be pursued in parallel. Eventually we are going to see a very diverse range of cements, which are adapted to locally available materials. But diversity means performance questions will be more and more complicated.
• For researchers to support sustainability, they must provide end users of concrete information that will make them confident about the use of the SCMs. This means having relevant performance tests. In particular, researchers need to know how to start with the variables—the composition of the cements, the SCMs, mixing techniques, curing times, relative humidities, etc.— and from this predict performance.
• Short term performance can be relatively easy to predict in the laboratory, but long term performance—where we expect structures to last 40-50 years without hardly any maintenance—is much harder to measure in the lab.
• Therefore, researchers have to pursue mechanisms to predict microstructure via advanced modeling techniques to pull all of this complex information together and have it make sense.