Material Science & Technology

1.8.1 SCIENCE, TECHNOLOGY & SERVICE

Commissioning of Fine Coal Treatment Pilot Plant

CFRI has designed and commissioned the Fine Coal Treatment Pilot Plant (FCTPP) as a low profile building (less than tree height) with state-of-the art process equipment for carrying out R&D studies on small/fine size coal. The MCC, Control room and the conference room are in a R.C.C. frame building, separated from the steel structure plant by an isolation gap of 50mm, to avoid vibration of the running equipment. The raw coal section of the existing coarse coal washing pilot plant has been enriched with a Batch Rotary Breaker of standard diameter (3.5 m) and a set of online crushers working on different principles like compression, impact, etc. The plant is equipped with secondary crushing house for further size reduction of, either raw coal/deshaled coal/middlings or sinks to finer sizes. FCTPP provides the following beneficiation processes: heavy medium cyclone, spiral, oil agglomeration and flotation. The online sensors and instruments like belt weightometers, load cells for bunkers, weigh feeders, mass flow meters, density gauges, energy meters etc., will help to optimize plant efficiency and economy for achieving desired level of cleaning/beneficiation with maximization of yield. The most important and attractive feature of the plant is that the entire installation including the existing plant can be operated from the control room, through PLC. The instantaneous mass flow of materials may be observed from the control room and its integration is recorded. The dosing/flow of process liquids may be controlled from the control desk as per the requirement of the process. These state-of-the-art facilities may help to develop the optimum beneficiation circuits for the treatment of inferior coals both coking and non-coking.

The FCTP Plant

Biometric synthesis of inorganic nanoparticles under microgravity

NML has designed and fabricated a biometric reactor to be installed as a payload on the first flight of recoverable space capsule being planned in 2005 by Indian Space Research Organization (ISRO). A conceptual design for Biometric synthesis of inorganic nanoparticles under microgravity has been made and a prototype reactor has been fabricated. The payload review committee of ISRO has approved this design.


Diamond reinforced composite (DRC) coating

Diamond and diamond based composite coatings are considered as superhard materials and harder than other materials. Due to their superior tribological properties, these materials are industrially important. It is difficult to make any component only using diamond powder. This has necessitated the growth of composite markets throughout the world. The diamond-reinforced composites have been used for the fabrication of diamond polishing wheel, diamond wafer blade for precision cutting, stone cutting wheel, metal scooping tools etc. Though significant amount of work has been done on the development of diamond-based composites, their processing parameters and tribological behaviour are not studied adequately or reported in the literature. In this project, an attempt has been made to develop a mixed metal powder consisting of C, WC and Cu. The microstructural observations showed a uniform distribution of all the phases and were uniformly distributed. The particles of diamond are in the range of 2-3 microns and WC of 15-20 microns. The flow of the composite coating during the spray deposition appears to be good and coating thickness is uniform. Further, the bonding between the coating and substrate looks good. The coated substrate has been cut into 8 x 40 mm2 cylindrical in shape and sliding test under 1Kg and 2Kg are conducted. The results shows that due to the presence of hard particles in the mixed metal powder and also having a good bonding among the phases, the coated sample did not worn. In addition, the standard steel disc with hardness 65 Rc has been worn out and during the test the samples gain the weight, instead of loosing the weight that results in negative wear results. The results strongly suggest that the coating can be used for a high wear resistant material.

Eco-friendly Cokeless Cupola

A gas-based cupola of 3t/hr was engineered and installed in the premises of M/s Goel Engineering Works, Agra in 2001 by M/s Tata Korf Engineering based on NML's know-how and technology. The process parameters for 2t/h cokeless cupola earlier operated at Agra were again examined, analysed and optimised in the scaled up cokeless cupola of 3t/h operation. These trials of 10t to 15t conducted in two phases have now been successfully accomplished. The results and optimized parameters are: temperature from 1380oC to 1420oC without oxygen, good flowability of slag/metal, thin casting ( for pipe & pipefitting) and thick casting (drain cover etc.) of which around 95% are acceptable, depending on requirement temperature is controllable, smooth deslogging, controllable system pressure. The present system indicates that the cupola can be operated on alternate days and the furnace can achieve melting at the rate of 3.8t/hr which is 25% more than its rated capacity at the rate of 3t/h.

Studies on retained austenite in life expired rotary slide valves of centrifugal governor of main fuel pump of R-25 Aeroengine of MIG-21 aircrafts.

NML investigated the fusion of rotary slide valves (RSV) of MIG 21 aircrafts involved in three Cat-I accidents at Jodhpur, Ambala and Jaisalmer. The results indicated that the retained austenite in the material and contaminants in the fuel system are responsible for the fusion of RSV. The contaminant abrasive phases in the fuel system leads to the abrasive wear of governor-end guide-land that generated heat due to friction. It, however, gives rise to increase in temperature upto 500oC-550oC in affected localised circumferential band. The heating is sufficient to transform metastable retained austenite into martensite during cooling. The frictional heating is only caused by larger abrasive contaminants because the smaller size abrasive contaminants easily escaped after forming short wear tracks on the guide land. The generation of frictional heating, therefore, depends on the size of abrasive contaminants. The phase transformation of retained austenite gives rise to local expansion at the guide land leading to fusion of RSV. During the intervening period, a number of cases of fusion of RSV at test - bed/rig are observed. As the retained austenite is deleterious in a component requiring high dimensional stability therefore, it was decided by Indian Air Force (IAF), Hindustan Aeronautics Limited to quantify the retained austenite in the RSV and find out the critical amount needed for dimensional changes sufficient enough to cause fusion of RSV.

Roll Rail qualification tests

NML has conducted Roll rail qualifying test for M/s Jindal Steel & Power Ltd., Raigarh. Fracture toughness measurements, fatigue test, inclusion rating and residual stress measurements are carried out as per the IRS T 12-96 standard. Fracture toughness measurements showed crack path was within permissible envelope. The specimens qualify the requirement as per IRS-T-12/1996, clause 22.2.6. Since the IRS-T-12/1996 is not very clear about fatigue test details, it is assumed that the relevant ASTM test standard is E 466 and not E 606. The specimen passes the minimum requirement of 10 million cycles as per IRS-T-12-1996, clause 22.3.3. The inclusions, as analysed by image analysis software package, were observed to be considerably lower than the limits specified by IRS-T-12-1996, clause 22.4.1. The maximum size for both thick and thin series of all A, B, and C and is 0.6, as compared to 2.5 in the specifications. The residual stress measured as per IRS-T-12-1996 (22.1.2) showed all the stresses, except in the centre line of head and foot for samples, are below the limit of 14% UTS of rails. The exceptions mentioned also exceed only by 2%. Such higher stresses in the centre line are commonly found in the literature. Roll rails are found to qualify all the tests according to the specified standards.

An improved method for Underground Extraction of coal from contiguous Seams/Sections

Underground extraction of clean coal from thick and contiguous seams/sections in presence of weak and laminated parting in-between is a major problem of the Indian coal mining industry.

CMRI has conceived an idea of underpinning to facilitate safe and optimal extraction of coal from such seams/sections. The system involves conventional system of development of the sections of the seam/seams along the floor with superimposed pillars and final extraction by splitting and slicing by reinforcing the parting from top of the seam/section working with the application of used wire ropes in galleries/splits/slices.

CMRI found that underpinning consolidates parting stability through reinforcement and provides additional thickness to the critical parting as the roof coal band of the thick bottom sections was stitched together with the parting.

This technology was introduced at Chirimiri colliery of SECL for simultaneous extraction of contiguous sections of zero seam with critical and laminated parting of approx. 3m thick. This method arrested failure/collapse of parting and provided support of high roof during workings of bottom section of approx. 6m thick. This system has successfully been implemented for optimal extraction of 26 panels of the seam. The method has now been accepted as a regular system of extraction for rest portion of the seam.

This method has increased not only the life of the mine but also the mineable property in addition to manpower deployment opportunity. In addition to safety and productivity. Total value of coal of Rs.167 crores would be possible to mine from this seam by the implementation of the method.

Improved inorganic cement capsule developed for quick setting of bolts

Full column cement grouted roof bolts are gaining immense popularity as a very suitable method of roof supports, as they are economical and effective under Indian strata conditions for underground mines. These bolts provide reliable anchorage by preventing bed separation due to bonding between the strata and the bolt.

CMRI has developed an inorganic composition for grouting the roof bolts. The composition contains all the requisite key features like instant grip, high early and ultimate strength, non-flammable, non-corrosive, non-allergic, and has good self-life and performance of anchorage

The developed grouting mixture has been put under field trial at a colliery of SCCL. The result is satisfactory and it has shown an anchorage strength of 3.0t after 30 min. of grouting and 5.0t and above after one and half hours of grouting. This mixture is expected to be very useful for immediate supporting of freshly exposed roof rock of underground mines.

Air Dense Medium Fluidized Bed Separator for Dry Beneficiation of High Ash Non Coking Coal

Most of the non-coking coal reserves in India contain high ash content ranging from 40-45%. It is necessary to beneficiate these coals before utilization in power generation, sponge iron making, cement manufacture etc. Beneficiation can be carried out by wet or dry methods. The technologies for beneficiation by wet methods are well established but dry techniques are yet to be commercialized. The dry coal beneficiate has become important due to several advantages. With this background, RRL, Bhubaneswar has developed an air dense medium fluidized bed separator to reduce ash from Indian non-coking coals. A prototype set up has been designed, fabricated and tested. In pneumatic dense medium separators, a medium is created by suspending solid particles in an upward airflow. By means of gas-solid two phases pseudo-fluid as beneficiation medium, the light and heavy materials stratify in the fluidized bed according to density. The dynamic stability of the medium plays an important role in the sharpness of the separation and the system should operate under particulate fluidization. Laboratory models of different geometries were used for these studies, where the magnetic powder below 45-micron size was fluidized by compressed air at the different airflow rates to create the dense medium. Based on this basic study, a laboratory model of dense medium fluidized bed separator with capacity of 600 kg/hr was designed and fabricated to carry out the continuous study of the system. Trial runs with different process variables have been conducted. The results show that the ash percentage could be reduced from 40% to 30% with 70% yield.

New method to utilize Steel Plant waste economically -Briquetting

Steel industry generates a lot of waste materials such as iron ore fines, mill scale, coke breeze, flue dust, SMS sludge, stock house dust, lime dust, etc. These wastes are fine in nature. They not only attribute to huge loss of valuable resources but also cause environmental pollution. Hence, recycling of these wastes becomes necessary to solve the above problems. Moreover, reclaiming of iron and carbon units, which have already been paid for, can contribute to lower production cost. Thus, processes to recycle these byproducts/waste materials have been a concern of the iron and steel industry for many years. These wastes being fine in nature cannot be recycled directly. Various agglomeration techniques are adopted for making them suitable for recycling. Among the various agglomeration techniques, the cold briquetting offers greater flexibility for particle size of materials and binders. Hence, RRL-Bhubaneshwar utilized the waste generated in the steel plant, in the form of cold briquettes that are suitable for the blast furnace operation. Laboratory scale studies have been conducted on cold briquetting, using inorganic binders to achieve high green and cold crushing strength. On the basis of the results, large-scale trials on 30 tph capacity have been successfully conducted at the plant site of M/s. Ispat Metallics India Ltd. The briquettes produced during the trial runs have undergone various metallurgical tests such as RDI, Tumbler Index, etc. and found to be suitable for charging to blast furnace.

New technology developed to manufacture DRI blocks by utilizing the Iron bearing fines and coal/char/coke fines for use in steel-making

There has been considerable interaction over the year in finding an efficient process in agglomeration for utilization of ore fines, concentrates, waste and solid fuels for conservations of minerals and recovering energy values from waste fuel fines. Briquetteing technology is efficient process on agglomeration of ore fines.

In metallurgical industries, large quantities of iron ore fines and coal/char/coke fines are also rejected as waste. At present, a part of these solid wastes are sold at a throwaway price resulting substantial financial loss and a bulk of these are stock piled causing waste disposal and environmental problems.

RRL-Bhubaneswar has developed a process to produce composite blocks of iron ore fines and solid waste fines using suitable binder combinations followed by reduction roasting in non-oxidizing/mild reducing condition in a coal fired furnace. These highly metallised DRI blocks can be charged into the induction furnace for steel making. This new technological development consists of (a) utilization of iron oxide bearing fines and coal/char fines in the form of composite blocks, (b) development of thermally stable inorganic binder combination, (c) reduction of iron oxide in composite block in a coal fired furnace keeping reducing/non-oxidizing atmosphere, (d) the technology is less energy consuming and solves the disposal problem of fines with value added product. This is a new and simple technology for making steel by utilizing waste fines generated in the mines as well as industries and is proposed for the first time in the country.

NEW FACILITIES CREATED

NML

  • ZHE Hazardous Waste System
  • Siroquant quantitative XRD phase analysis software
  • Oscillation stage for Seifert XRD 3003 PTS
  • LaboTex-The Texture Analysis Software for Windows-single user License, version 2.1, PC version
  • Softwares: NAG Fortran Library, NAG C Library, IRIS Explorer and NAG Graphics Library
  • Curing Tank, 1.5M x 0.75M x 0.5M SST 144 curing chamber with accessories
  • Abrasion Tester with accessories, Model TR-605
  • Dry Abrasion Tester with accessories, Model TR-50
  • Atomic Force Microscope
  • Lab VIEW Full Development System for Windows 2000/NT/Me/9x
  • Laser Flash Thermal Constant Measuring unit with accessories
  • Hand Held Thermal Imaging System Agema 550 with accessories
  • Leica DMLB HC Transmited Light Biological Microscope
  • Planetary Ball Mill Single Bowl with Agate Bowl 80 ml with Agate Balls
  • Bench Top Reactor
  • Ultrasonic flaw Detector
  • Energy Dispersive X-Ray Spectrometer
  • PC Based Ultrasonic Flaw Detector
  • Single Disc Polishing Machine with accessories, spares & consumables
  • Differential Scanning Calorimeter and Thermogravimetry
  • Proof Ring Assembly with contaminant vessel

1.8.2 HUMAN RESOURCE DEVELOPMENT

CFRI

  • Training programme for the staff of DPL, Durgapur
  • CPYLS Programme on 14th -15th January, 2004
  • Reorientation programme for the CSIR Diamond Jubilee Interns
  • Students Excursion
    • Twenty six (26) students of M.Sc. (Geology) from Jadavpur university, Kolkata visited CFRI on 7 Nov. 2003 and got acquainted with the working of the labs. of Coal Constitution, Research Quality Assessment, Coal Preparation, Coal Petrography and Environment Science.
    • Thirty two students of B.E (Chem. Engg.) from BIT, Sindri visited Coal

NML

  • Training on Advanced Mineral Processing Methods imparted

Training undergone by Scientists/Technical Officers

  • ISO Lead Auditor Training (3 scientists received training)
  • ISO-9001: 2000 Awareness Training (30 scientists received training)
  • Training on R&D Management (1 scientist received training)
  • Deputed to undergo training: 10 persons
  • Deputation to Seminars/Workshops: 35 scientists/staff
  • Training of staff: Training on 'ABAQUS' FEM software package- 15 Scientists
  • Training on Management-1.
  • Training on Administrative Matters-1.
  • Training on Safety-1.

1.8.3 RECOGNITION & AWARDS

1.8.3 RECOGNITION & AWARDS
NRDC Technology Award Drs. K. Sen and D.K. Chakraborty, CFRI
IIME Mineral Beneficiation Award - 2004"by Indian Institute of Mineral Engineers, for outstanding professional contribution to Minerals Engineering. Dr. Vibhuti N Misra, RRL-Bhubaneshwar
“Samanta Chandra Sekhar Award” for the year 2001 in recognition of his significant contribution in Physical Sciences in the State of Orissa by Orissa Bigyan Academy.  Dr. K. M. Parida, RRL-Bhubaneshwar
MECON award by Indian Institute of Metals for the year 2003 NMD, ATM, Kolkata for the design & development of air dense medium fluidized bed separator for beneficiation of non-coking coal. Dr. S. K. Biswal  and  Ashok K. Sahu, RRL-Bhubaneshwar
Indian Institute of Metal, Bhubaneswar Chapter, Award for the year 2003. Mr.  B. Bhoi, RRL-Bhubaneshwar
Fellow of National Academy of Sciences, India Prof. S.P. Mehrotra, NML
MRSI Medal in the field of Materials Science & Engineering  Dr. Suman Kumari Mishra, NML
Raman Research Fellowship (CSIR), 2004  Dr. K. Venkateswarlu, NML
Boyscast Fellowship (DST)  Dr. Raghuvir Singh, NML
Gold Medal of The Mining, Geological & Metallurgical Institute of India 2002-2003  Shri R.K. Jana , NML
19th IETE Bimal Bose Award, 2002-2003 Dr.S.K. Mandal, NML
Distinguished Services Award Smt. Savitri Iyer and Sri H.C.Gope, NML

President’s visit to NML

Hon’ble President of India His Excellency Dr. A.P.J. Abdul Kalam visited NML. During his visit he had addressed the gathering and interacted with scientists of the laboratory.

President at NML

Hon’ble President recorded on visitors’ book “I am indeed delighted to interact with Scientists and Engineers of National Metallurgical Laboratory. It is a competitive world where in we have to work hard and provide inputs to our production institutions to gain technological advantages in product design and production.”