A graph of the annual market value for the U.S. refractories industry, from 1970 to 1992 is shown in Figure 1. The total market value first exceeded $1 billion in 1974-75, and surpassed $2 billion in 1989 and 1990. In 1991 and 1992 the total market value declined slightly to less than $2 billion. It can be seen that over the last five years, the market value of clay (traditional) refractories has decreased slightly and the value of non-clay refractories has increased slightly.
Figure 1. Annual market value (US$) for the US refractories industry, with a breakdown of the clay and non-clay types (data from the US Department of commerce).
Employment in the US Refractories Industry
In the late 70’s, when steel production was high (130-150 million tons), the refractories industry had more than 20,000 employees. But with the decline in steel production to <90 million tons in the early 80’s, the refractories employment decreased rapidly to about 12,000 in 1983. Thereafter, the number of employees in the refractories industry increased steadily, and has stabilised in the 14,000-16,000 range.
The Effect of Refractories Development
Over the decades, the refractories industry has been very successful in providing new and improved products and services for the consuming industries, on an ongoing basis. These efforts have contributed to the ongoing reduction in the refractory consumption rate in the steel industry, as discussed above. For the future, based on U.S. refractories production for the five year period 1988-1992, the following projections result:
Total refractories production
Total market value
Future Trends in the US Refractories Market
Given the projected reduction in overall refractories production and value, there likely will be more streamlining, mergers, and buyouts as well as reduced R&D activities, testing, meeting participation and attendance, technical marketing services, quality control. etc. But some of the large and small U.S. refractories companies have recognized the needs and opportunities worldwide, and have increased their R&D commitment to enhance their future business potential.
Review of Selected Refractory Topics
Raw materials are essential to refractories technology, both for current production and for future improvements and innovations. Refractory manufacturers constantly search the world for raw materials that are new, improved, cheaper, more consistent, higher purity, sole-source, etc. In general there has been an increased awareness of the importance of particle size grading in refractory formulations, especially the sub-sieve fractions, including more use of ultrafine and fumed materials, which result in significant property improvements. The importance of organic (including carbon/ graphite), inorganic (both oxide and non-oxide) and metallic additives has been recognized and proven effective for property and performance enhancement of refractories. Advanced refractories containing up to four classes of raw materials (earth materials, metals, ceramics. and organics) are not uncommon today. Today refractory formulations range from simple, with one size-graded raw material (e.g. magnesia), to complex, containing up to 10-15 different constituents.
Manufacturing/Firing of Refractories
Manufacturing improvements and advances are essential as the technology and complexity of refractories changes. For example, the manufacture of advanced castables (low-, ultralow, and no-cement types) requires sophisticated capabilities and control because there are important additives in very small amounts (<1 wt.%) that must be consistently and uniformly dispersed to achieve optimum properties. Similarly there are advanced brick products that contain additives which must be thoroughly dispersed to fully achieve the desired benefits.
The development and implementation of total productive maintenance (TPM) programs will provide the basis for improved efficiency and increased production, by changing the interaction and activities in the workplace, and reducing the maintenance/ downtime of production equipment.
There have been, and will be, continued advances in the firing of refractories, that permit the manufacture of more consistent products, usually with improved properties. Improved burners, new temperature and atmosphere sensors, computer controls, and higher temperature kilns (up to 2800°C) are a few notable areas of advancement. But it must be realised that the firing of refractories is an energy and cost intensive aspect of manufacture, and there has been a progressive increase in the manufacture/ use of monolithic refractories, which do not require firing for manufacture. Monolithic products now account for roughly 50% of the refractories market and that figure will continue to increase. Thus it can be expected that the production and use of fired refractories will progressively decrease in the future.
Statistical Process Control/ ISO 9000
Most refractories companies in the U.S. know the importance of statistical process control (SPC), and have devoted significant time and money to personnel training and the methods/ equipment to achieve improved product quality and consistency. But despite the availability and use of the sophisticated techniques for maintaining excellent consistency and quality of refractory production, there are still times when off-quality product reaches the marketplace to the great displeasure and expense of the customer(s), and the embarrassment and expense of the manufacturer. Because of the occasional variations in refractory quality, many refractory users still employ their own audit procedures. So more effort is needed in the refractories industry to further reduce and eliminate the periodic departures from consistent, high quality production.
With the increased globalisation of the marketplace, the need has arisen for one recognised, independent system to Insure that commercially supplied products meet accepted International quality standards, i.e., “to provide a level playing field (pitch)”. To meet the need(s), in 1987 the International Standards Organization issued the ISO 9000 series of standards (9001, 9002, 9003, 9004) for insuring consistent quality production. Previously most of the industrialised nations mainly relied upon their own standards, which were product specific. So there were differences and redundancy in the evaluation and comparison of the properties and quality of refractories. The ISO 9000 standard is generic, and is applicable to the manufacture of any product or service. It is a highly structured, detailed documentation system that covers all aspects of the manufacturing process. So like the SPC and Deming management principles that were the prevailing quality guidelines of the 80’s, ISO 9000 has rapidly become the world standard for quality control in the 90’s. Currently most U.S. refractories companies are in various stages of the ISO 9000 certification process; i.e. some have received certification and others are just beginning.
With the increasing requirements for consistent quality production, and rising labour costs, the refractories industry (and others) needs to carefully consider more automation. The availability of robots and other automated equipment for forming, finishing, handling, setting, transporting, and testing, offers the opportunity for more consistent and accurate forming, increased productivity, labour reduction, improved cost efficiency, and many other practical and economic benefits.
The refractories committee (C-8) of the American Society for Testing and Materials (ASTM) monitors all refractories testing activities. Some of their main functions include overview of the practical, technical, and editorial aspects of all current standard tests, critical evaluation of tests (such as precision and accuracy, and ruggedness determinations), recommendation of changes/ improvements, development of new tests, and elimination of outdated or unneeded tests.
In general, there has been increased usage of higher temperature and more sophisticated tests, especially those involving simulative atmospheres, mechanical characterisation (strength, creep, etc.), computer control, and model correlation. Also, many of the traditional tests that have been used routinely for decades are still extensively used.
The refractory users especially want to be provided more meaningful exposure test data, from tests that reflect or simulate service conditions, as well as other tests to simplify the comparison and selection of refractories, and properly justify authorisation of service trials. Steel industry people indicate that such data have become less available in recent years, which has increased their difficulty of evaluating and comparing products, and justifying trials. The legal and economic ramifications of authorising a refractory trial now require much greater precaution. For a refractory company to gain acceptance of an improved or new product, it is increasingly insufficient to present only traditional test results, or results from a “successful” trial(s) elsewhere. It is well known that the refractory performance in the “same” kind of furnace can be widely different between two companies, and even between two works of the same company.
There is increased evaluation and development of refractory lining design by computer, using various software programs (e.g., Algor, ANSYS, REFSAM, RESGAP, etc.). Numerous practical benefits have been achieved from these efforts. To further enhance the use of these sophisticated methods, it is necessary to increase the availability of the applicable test data and to develop a valid database with internally consistent property data that are incorporated from worldwide sources.
Many significant improvements and advances have been made in monolithic refractories over the last 20 years. Especially castable refractories have been improved with development of low cement, ultralow cement, and no cement types, as well as rapid fire and metal fibre containing varieties. Low cement, self flowing castables are a more recent development, that are used for intricate shapes or structures, without the need for vibration, and without the segregation tendency that accompanies the over watering of low cement castables to make placement easier. Likewise there has been ongoing improvement in plastics (mouldables), gunning mixes, ramming mixes, and mortars. The result has been increased usage of monolithic refractories as pre-cast shapes and site installed original linings or repair/ maintenance materials, throughout the consuming industries. Like other industrialised nations, monolithic refractories now account for roughly half of the total refractories market in the U.S.
The continued development of new and improved refractories requires the continuous monitoring of a wide range of topics and fields. These efforts provide the newest and best concepts, techniques, materials, instruments, equipment, etc., that can be used to optimum advantage. The exchange of information between technologists of different background and experience can provide valuable benefits. The following topics/areas can offer significant contributions to the ongoing advancement of refractories technology:
• Phase Equilibrium Studies - especially for non-oxide and mixed oxide-non-oxide systems, in controlled atmospheres, or air if appropriate.
• Engineered Microstructures - such as oriented intergrowths, in situ fibre development, homogeneous/graded aggregate coatings, novel fused materials, particle toughening and metal-containing compositions.
• Additives and Mineralisers - including organics, inorganics, and metals. The associated use of sophisticated techniques (e.g. colloidal processing, freeze drying, reaction sintering, etc.), coupled with improved understanding of the particle interactions and chemical effects, will result in new and improved refractories, especially of high value type.
• Advanced Materials and Processes - like cermet and composite materials produced by directed oxidation, combustion synthesis, and freeze moulding are several examples that hold promise for refractory applications.
• Microwave Equipment - for dryout and firing of refractories.
• Firing Conditions - including higher temperatures (up to 2800°C) and controlled atmospheres (such as reducing), with or without pressure, offer benefits for refractories.
• Computer Technology - such as tomography and design software, should be investigated and used to advance the understanding of details of refractory forming, optimised lining design, and many other concepts.
The U.S. refractories industry, like the iron and steel industry, is in a period of transition, with a variety of significant changes to occur over the next 10+ years. The specifics of the changes can’t be predicted yet, because neither the details nor the timing of the changes in the iron and steel industry and the other refractories consuming Industries, are known at this time.
With the cutback or elimination of refractory departments at the steel companies, the refractory companies have an opportunity to become more actively involved, and develop better knowledge of the current and future steelmaking processes, from start to finish. This collaboration can promote more interaction, and possibly partnership development, which can improve product development, improve technical support, reveal needs and opportunities in a timely manner, and enhance the potential for field trials of new/improved refractories and installation/maintenance techniques.
Historically, the refractories industry has been very successful in developing and supplying new and improved products to the consuming industries, on an ongoing basis. Despite the continuing efforts and successes in providing more cost effective products, with significant economic benefits for their customers, the U.S. refractories industry is concerned that their efforts are neither fully appreciated nor adequately compensated. The quotes by a refractories company president Illustrate the concerns:
“Each time a technical improvement is made (in refractories), there is a reduction in market potential.”
“Refractories are high-tech products which are mostly being sold as low-tech commodities.”
So the U.S. refractories industry has numerous concerns for the future, such as indicated above, as well as the following:
• Imported refractory products
• North American Free Trade Agreement (NAFTA)
• Global markets and currency status
• Declining refractory consumption rate
• Changing refractories use trends
• Reduced research funding
• Change in refractories education
• Environment, safety, and health
• Disposal and recycling of used refractories
Another refractory company president has stated that “The most unpredictable part of the refractory industry’s future may be the safety, health, and environmental costs.” Thus the Refractories Institute, which is the industry trade association, continuously monitors these areas with active committees and an as-needed presence in Washington, D.C.
Given the continued reduction in the refractory consumption rate, and the associated projections of decreased overall refractory production, it is likely that there will be further downsizing of the U.S. refractories industry, with streamlining, mergers, buyouts, etc. There will certainly be opportunities for refractories companies to prosper with active and timely, domestic and global involvement. Important will be aggressive monitoring, critical evaluation and selective action. The opportunities have been recognised by several large and small refractories companies, who have begun to upgrade their R&D facilities and programs during the last year.
The refractories industry is a very important, ever changing field, and those characteristics are not going to change. But the refractory companies that continue the traditional. Business-as-usual practices, can expect a progressive decline in business. However, the dynamic and aggressive companies will continue to grow and prosper. It is definitely an interesting and challenging time for the U.S. refractories industry, with ample opportunities for practical, technical, and business successes, based on the continuing requirements and new needs for all of the refractory consuming Industries.
Note: A full set of references are available be referring to the original text.