Tire Rubber Recicling
Energy-Efficient Technology for Recycling of Tire Rubber Using Explosive Cutting Followed by Shear Grinding
Tech Area / Field
- ENV-SPC/Solid Waste Pollution and Control/Environment
- MAT-ELE/Organic and Electronics Materials/Materials
3 Approved without Funding
VNIIEF, Russia, N. Novgorod reg., Sarov
- Russian Academy of Sciences / Semenov Institute of Chemical Physics, Russia, Moscow\nJoint Stock Company "Novy Kautchuk", Russia, Moscow
- University of Strathclyde / Department of Pure and Applied Chemistry, UK, Glasgow\nMartin-Luther Universität Halle-Wittenberg / Institut fuer Werkstoffwissenschaft, Germany, Halle\nCentral Michigan University/Center for Applications in Polymer Science, USA, MI, Michigan\nUniversity of Alacant / Analytical Chemistry Department, Spain, Alacant\nCase Western Reserve University / Department of Macromolecular Science and Engineering, USA, OH, Cleveland\nUniversidade de Coimbra, Portugal, Coimbra\nPolytechnic University / Polymer Research Institute, USA, NY, Brooklyn\nUniversidade de Coimbra / Departamento Quimica, Portugal, Coimbra\nThe Second University of Naples, Italy, Aversa
Project summaryThe goal of the proposed project is development of an energy-efficient environmentally-safe technology for recycling of worn-out tires of automobiles and planes by step-by-step grinding of them.
The problem of recycling of worn-out tires is urgent for all countries of the world in the environmental and economic terms, since more than 15 million tons of this type of wastes is piled in the world for a year. In particular, only in Russia, 700-900 thousand tons of worn-out tires from mine dump trucks are accumulated every year. At the same time, molecular structure of tire rubber and structure of polyamide, which is used for cord fiber, is actually unchanged during operation. This gives opportunity for reuse of the mentioned valuable polymer materials, and, without saying, for reuse of steel cord. However, worn-out tires are usually burnt or buried. The reason is that majority of presently available methods for recycling of worn-out tires, which are based on burning, devulcanization and grinding by the existing methods, appear to be disadvantageous from the environmental or economic points of view.
It is planned at the first stage of the suggested Project to take account for expertise of efforts under the frameworks of ISTC Project ¹1787 and to perform explosive cutting of automobile tire covers with additional separation of thread and other fragments containing no metal cord from them. Then it is planned to perform final grinding of tire rubber fragments up to stage of formation of thin rubber powder (with particle sizes of 10-500 m and specific surface of 0.3-3 m2/g) with use of the unique method of high-temperature shear grinding (HTSG) of polymers, which was developed in ICP RAS.
Expected Results and their Application.
The following results will be obtained under the project framework.
- Laboratory and industrial models of the facilities of energy-saving explosive cutting of worn-out rubber tires, including large-size tires with separation of thread and other fragments of rubber containing no metal cord will be created. Application of the above-mentioned facilities, including in the field conditions, will allow to produce rubber semi-product for further thin grinding of it in rotor dispersers.
- Theoretical bases will be created for the technology of thin grinding of tire rubber in conditions of intensive shear stresses at comparatively high temperatures (140 -
170оС) due to occurrence of explosive, avalanche-like cracking of rubber. Shear stresses and temperatures, which are optimum for minimizing energy input for rubber grinding, will be calculated.
- Optimum energy-saving regimes for operation of the laboratory and industrial dispersers will be experimentally verified for production of active thin rubber powders (with particle sizes of 10-500 μm) and rubber crumbs (with particle sizes from 1 to 2.5 mm), which are required for various industrial consumers.
- Demonstration of operation of the mentioned facilities will be performed.
- Suggestions will be formulated on purchase of grinded rubber from planes and automobiles by plants of the general mechanical rubber industry, motor car construction and road-building, the RF Ministry for Emergencies (to liquidate man-caused accidents during spillage of large quantity of oil products on the ground), manufacturers of noise-proof screens mounted at roadsides.
Scientific value of Project consists in:
- revealing of the fact that explosive grinding of rubber can be performed both at the first stage of its processing (during cutting for parts with use of explosives) and at the final stage of production of thin rubber powder under conditions of effect of high shear stresses on rubber at optimum high temperatures;
- obtaining unique information on behavior of polymer materials under dynamic loading;
- obtaining new, maximum high-disperse (with specific surface up to 5m2/g) rubbers and composition materials based on these rubbers;
- development of scientific bases for the technology of explosive grinding of retired polymer-containing materials, including tire rubber.
Commercial value of Project is creation of industrial sites for recycling of worn-out tire covers through production of high-disperse rubber powders and rubber crumbs from them with further selling of these materials to interested plants.
Project meets ISTC goals and objectives, since it:
- provides weapon scientists and engineers with opportunities to redirect their talents to peaceful activities;
- supports applied researches and development of technologies for peaceful purposes, especially in saving the environments;
- supports transition to market economy facilitating civil applications.
Scope of Activities
VNIIEF scientists will:
- develop a design of the facility for explosive cutting of automobile tires of various types and sizes with separation of tread and other fragments of rubber, which don’t contain metal cord;
- verify the design of wear-resistant metal cutters for automobile tires;
- verify the regimes of acceleration of the metal cutters to be optimum in energy input;
- manufacture operational model of the specified facility;
- verify energy-saving procedure of the first stage of automobile rubber grinding with use of the operational model;
- prepare and perform demonstration of the technology for explosive cutting of automobile tires..
ICP RAS scientists will:
- perform experimental and theoretical study of possibility for optimization of thin grinding of tire rubber with use of laboratory and industrial rotary dispersers;
- develop optimum (in terms of energy input and quality of produced products) technology for thin grinding of rubbers from automobile tires of various types by industrial rotary disperser;
- perform preparation and demonstration of application of the most advanced technology for tire rubber grinding by industrial rotary disperser.
JSC «Novy Kautchuk» experts will:
- develop a wear-resistant rotor for the industrial disperser of polymers, which will provide long-time operation of this disperser without repairs with efficient thin grinding of tire rubber (with productivity up to 200 kg/hour);
- manufacture an operational model of the disperser with use of more wear-resistant rotor;
- perform preparation and demonstration of operation of the manufactured disperser with use of rubber from tire cover of one type as an example.
Scientists and experts from RFNC-VNEEF, ICP RAS and JSC «NK» will formulate proposals for application of industrial facilities and technologies, which they developed for explosive cutting and high-temperature shear grinding of tire rubber.
Thus introduction of the developed technology to practice will allow to solve the important world environmental problem of tire rubber recycling with minimum energy inputs. It will become possible to produce wide range of valuable rubber-containing materials with minimum prime cost.
The Project will be fulfilled by highly-skilled experts from RFNC-VNEEF and ICP RAS together with JSC «NK», who are well-known due to their works in Russia and abroad.
Role of Foreign Collaborators
It is planned to discuss the following issues with the collaborators:
- work plan of the project;
- list of diagnostic techniques and equipment for conduction of research experiments aimed to verify regimes of operation of the facilities;
- method for demonstration of the developed technology;
- practiacal application of the technology.
Technical Approach and Methodology
To solve the project objectives, the following methods are planned to be used:
- energy-saving method for cutting of tires of planes and automobiles with use of a metal knife-impactor accelerated by explosion. Here it is planned to use standard HE as ammonite or other industrial HE, and explosion will be performed in a closed metal chamber;
- environmentally-clean energy-saving method of high-temperature shear grinding (HTSG), which provides production of high-disperse active powder. This method is used in rotor dispersers, where rubber is subjected to intensive compression and shear at optimum high temperature.
It is planned to use the set of theoretical and calculation methods in the work for development of experimental devices, which are capable to withstand explosive shock loading for long time.
Using the methods of theoretical and chemical physics, it is planned to reveal conditions of physical high-temperature destruction and grinding of tire rubber in the field of intensive shear stresses at optimum low energy input.
During research experiments, it is planned to use modern techniques for recording the required parameters with use of analog digital devices and computer processing of results.
The International Science and Technology Center (ISTC) is an intergovernmental organization connecting scientists from Kazakhstan, Armenia, Tajikistan, Kyrgyzstan, and Georgia with their peers and research organizations in the EU, Japan, Republic of Korea, Norway and the United States.
ISTC facilitates international science projects and assists the global scientific and business community to source and engage with CIS and Georgian institutes that develop or possess an excellence of scientific know-how.