Modernization of manufacturing facilities

Technologies and innovations

 

Modernization of the machining facilities

In 2018, the modernization of the machining facilities for the main products of the enterprise, i.e. graphite electrodes, began.

As part of the modernization, it was planned to carry out current repair of the building and install new machining equipment.

From 2018 to 2020, in the renovated, large and spacious building, two new automated machining lines for manufacturing large, medium and small electrodes, as well as automated nipple machining lathes and test benches were installed. The new modernized department of the machining workshop was equipped with modern aspiration and power systems, lifting and handling equipment.

The building also houses the departments for packaging, warehousing and shipment of finished products.

The new department in the machining workshop will be constructed at the end of 2020.

The new equipment will allow reaching a new level of machining quality for graphite electrodes and nipples.

Modernization of the baking facilities  

In 2018, the modernization of furnace No. 9-1 located in the third building of workshop No. 3 started according to the project of German company RIEDHAMMER, the world leader in the production of special furnaces.

From 2018 to 2020, reinforced concrete moisture protection pit in furnace No. 9-1, annular smoke flue and refractory lining of the furnace were installed, the furnace auto-baking system is being mounted, which will provide an energy-efficient technology for the first baking of electrode bodies in the furnace and high baking quality for products.

In 2018, the management of the enterprise decided to purchase and install 2 new car-bottom furnaces with raising gates for rebaking of products. Such equipment is characterized by high baking performance and guaranteed product quality. The operation of such furnaces is based on one of the latest energy efficient baking technologies at 850°C, which allows burning a part of the evaporating volatiles inside the furnace using low oxygen technology.

The mobile platform system being part of the furnaces ensures uninterrupted loading/unloading of products, and the thermal oxidation system with heat recovery ensures the environmentally friendly operation of the equipment.

From 2018 to 2020 preparatory work for the installation of rebaking furnaces were completed, and assembly work started.

The start-up of furnace No. 9-1 and 2 rebaking furnaces is scheduled for late 2020 - early 2021.

Also, as part of the modernization, in the third building of workshop No. 3, 2 (two) overhead cranes with a lifting capacity of 20 t were installed to replace worn-out cranes, new equipment for the filling material unit was manufactured and installed, new equipment for pneumatic removal of the packing material from furnace 9-1 will be supplied and installed.

One of the most important items of the modernization plan for the baking facilities   is the installation of new gas-treatment equipment for purification of flue gases from furnace No. 9-1 and existing furnace No. 10. This is a set of gas treatment equipment in which up-to-date technology is applied - the technology of regenerative thermal oxidation (RTO), in order to thermally destroy volatiles (oxidation reaction) escaping from the furnaces during the baking process.

All new equipment to be modernized and purchased has an automated control system. Automation of the baking processes at all its stages, including flue gas treatment, leads to an improvement in the environmental situation at workplaces and the overall environmental situation in the city.

With the commissioning of new furnaces, it is supposed to improve stability of carbon and graphite product properties, significantly reduce the consumption of natural gas, and the enterprise will also have an opportunity to expand the range of products and launch new types of products. The new RTO air treatment system will comply with European air quality standards (purification efficiency is 90 - 99%).

Modernization of the graphitization  facilities

In 2016, the construction of a graphitization department began, and expensive and high-tech equipment (transformer, pressure trolley, etc.) were ordered and the technology was tested on a pilot plant.

Graphitization of electrodes is conducted in electric resistance furnaces at a temperature of 2600-2900 °C. As a result of this operation, the crystalline structure and properties of graphite are artificially imparted to the carbon in the amorphous state.

In Q4 2017, a new building for lengthwise graphitization of carbon and graphite products with 8 furnaces was constructed. In 2019, 3 additional furnaces were also commissioned.

The introduction of a new technology for the graphitization made it possible to significantly improve not only the quality of products, but also, mainly, to stabilize their characteristics, which is most important for graphite electrodes used in high-power arc furnaces for steelmaking. Passage of an electric current directly through the entire electrode in the longitudinal direction, and not in the transverse direction, as the technology provides for old furnaces, made it possible to reduce the specific electrical resistance (resistivity) of graphite electrodes to 4.5 ÷ 5.5 μOhm•m. This makes it possible to improve their operational properties, as well as to use electrodes with a diameter of 500 mm, 550 mm, 600 mm, 650 mm at the consumer at higher current loads.

Trapezoid roller mills

From 2016 to 2018, four trapezoid roller mills of the MTW 138 type were installed at Ukrgrafit, that will directly improve the quality of the products.

Description of the equipment: MTW 138 trapezoid roller mill is the latest type of mill equipment. MTW-138 trapezoid mill incorporates all the best technical innovations from the mill technology and has a unique drive scheme, special lubrication system, air duct shape, etc. The bearing assembly of the main unit is sealed. The main parts of the mill are made of high-strength steel, which increases the strength of the entire mill, extending its  service life. The mill is automated one, it has low energy consumption and is easily adjustable.

Technological features of the roller mill can significantly reduce the structural imperfection of the material. The roller mill is a "dry" grinding device with a fully controlled process, in contrast to the ball mill, which is very difficult to control. Roller mill operation is based on crushing and partly on abrasion by rotating mixes, which are under the influence of centrifugal forces or spring forces, which ensures the preservation of the material structure. The destruction of the material in it occurs through a compression system using a shear force, that creates a number of additional positive effects, both technological and mechanical, which is especially important for products made from needle cokes.

Moreover, the use of roller mills makes it possible to produce a material with stable grain size distribution and specific surface area. 

Pneumatic chamber pump

In 2018, in workshop No.1 where carbon materials are produced, a pneumatic chamber pump for transporting bulk materials was installed, which ensured more stable production of material with a fraction of (1-0) mm  and to avoid hanging of the material along transportation routes.

The principle of operation of the pneumatic chamber pump is based on squeezing the material out of the chamber by compressed air. The pneumatic chamber pump operates according to the following cycle. When the upper disc valve is open, the pump chamber is filled with the required fraction, and after it is closed, air begins to flow into the chamber, which means the start of the pumping cycle. The air is supplied as long as there is material inside the chamber.

Changing the crane  over to the control from the floor level.

Since 2018, the cranes used by the enterprise are gradually being changed over to the control from the floor level.

The cranes are widely used in the workshops of the enterprise, as well as in the warehouses.

Overhead cranes, which are controlled from the floor level, are equipped with special panels that make it possible to control 3 movements: lifting the load, moving the bridge and moving the trolley. Devices of this type are easy to operate, they are compact and ergonomic. With their help, the operator controls the lifting mechanism from any convenient place. Suspension panels must be equipped with:

- Button to provide quick emergency stop;

- Reinforced feeder cable;

- Key interlock.

A specialist below can see where and how best to raise and lower the load. Another advantage is energy saving, cabin heating or lighting are not needed.

 In 2018. 8 cranes were changed over to the control from the floor level, in 2019, there were 9 cranes.

Pitch melter and mixing machines with electrical heating for workshop No.1


 

In 2017, modernization was carried out in workshop No. 1 with the arrangement of the receiving and processing station for dry granular coal tar pitch with an automated electrical heating system for the pitch smelting process (similar to that installed in workshop No. 2 in 2016).  5 mixing machines were also put into operation for the production of electrode paste and pitch pipeline for them, the heating of which was changed over from steam to electric one.

Availability of our own coal tar pitch processing station in workshop No. 1 will eliminate the need to transport liquid pitch from workshop No. 2, prepare pitch in the amount sufficient for production needs and, accordingly, reduce energy consumption and environmental impact. At the same time, the introduction of electrically heated mixing machines and pitch lines for them made it possible to completely change over the electrode paste production line to electric heating and to abandon the use of superheated steam in workshop No. 1, which had high losses with a significant length of outdated steam networks. In general, the modernization of the electrode paste production has made it possible to significantly optimize the operating process, improve working conditions and increase the efficiency of energy use - saving more than 3,000 Gcal of steam per year,  reducing the impact on the environment, and reducing the formation of greenhouse gases.

Pitch melter for workshop No.2

In 2016, modernization was carried out at the stage of preparation of coal tar pitch and mixing-and pressing in workshop No. 2. The modernization includes the arrangement of a receiving  and processing station for dry granular coal tar pitch with an automatic electric heating system for the pitch smelting process and the introduction of an electrically heated baking line for transporting the processed pitch to the mixing and pressing department in workshop No. 2.

The modernization and commissioning of up-to-date equipment made it possible to abandon the processing of liquid pitch supplied to the enterprise in railway thermal tanks, its pumping into steam-heated storage tanks and, thus, to increase the production standards, improve working conditions and productivity, and reduce the impact on the environment. At the same time, the change over to the electric heating made it possible to remove obsolete communications heated by superheated steam and significantly increase the efficiency of energy use by reducing the consumption of superheated steam by 4,500 Gcal per year. Accordingly, the reduction in steam consumption has made it possible to reduce the environmental impact by reducing the formation of greenhouse gases.

 

 

2016

 


Materials for the furnace lining.


At ISD Dunaferr, Hungary, on 08.07.2016 blast furnace No. 2  was successfully commissioned <http://www.dunaferrmagazin.hu/index.php/rovatok/aktualis/1307-befejezodoett-a-kohofelujitas>.  A full  set of  carbon and graphite part of the blast furnace lining, that is more than 750 tons of products was  manufactured by  PJSC "Ukrgrafit" in  2015-2016.


3 grades of graphite and carbon blocks, including micropore blocks, and also 2 grades of carbon-based pastes were used.


Technical divisions of PJSC "Ukrgrafit" were involved in the development of the design of the furnace lining, namely the central research laboratory, the technological department, the design department, etc.


Due to efforts of production divisions of PJSC "Ukrgrafit", test preassembly of 14 courses of block lining  for  BF No.2.  was carried out  in a timely manner


ISD Dunaferr possesses two operating blast furnaces. For today  both furnaces contain lining materials produced by PJSC "Ukrgrafit".  The  management of the integrated works prefers   those material on the basis of their  experience in operation of products to  European and Chinese manufacturers of similar products.


 


Graphite electrodes


In 2015-2016,  manufacturing of graphite monoelectrodes Ø 200-250 mm started.


After successful tests of trial lots of monoelectrodes we received an order for their  commercial  delivery.


The  monoelectrodes performed well that  allowed us to gain a new sales market.


For measuring geometrical dimensions of electrodes modern measurement instrumentation has been purchased. Machining is carried out by  modern  VIPER NC  lathe.


 


Large-block pastes.


PJSC "Ukrgrafit" launches manufacturing of a new type of large - block rectangular  Soderberg electrode paste (LBEP). At present  LBEP 400-900 mm  in diameter, 850-1100 mm long is produced. The distinguishing feature of the rectangular LBEP is that the above product does not require packaging and this  makes it possible not to use  expensive wood. Also the LBEP storage area at the consumer will be considerably reduced.


Launching of the rectangular LBEPs will make it possible to enter new sales markets in America, Africa, etc.


 


Cathode blocks for the most powerful electrolysis cells in the world.


In February 2016, PJSC "Ukrgrafit" delivered 3 sets of PB10 graphite bottom blocks 3980 mm for RUSAL, intended for  a new  РА-550 electrolysis cell, fundamentally new design  for  future RUSAL's plants and modernization of its existing plants. According to calculations, the capacity of the new equipment will increase in comparison with the previous versions of electrolysis cells - РА-300 and РА-400  by  50-80 % and will exceed four tons of metal per day.


Previously, it is with the use of bottom blocks manufactured by Ukrgrafit  the production of РА-300 electrolysis cells was launched which were installed at the Khakassky and Boguchansky aluminium plants. In 2006-2007 for start-up of  the Khakassky aluminium  plant Ukrgrafit delivered 8 thousand tons of bottom blocks.


 


             Cathode blocks with improved resistance.


According to arrangement with one of the world leaders in the production of aluminium in the Middle East, for 2016 delivery of two grades of graphitized bottom blocks with the increased resistance to abrasive  wear  for operational tests was planned.


It is common knowledge that graphite bottom blocks have one disadvantage, that is 1,5 to 2 years shorter  life time, than that of anthracite and graphite blocks, accordingly, due to higher wear. Better resistance to abrasive wear of graphite blocks solves the problem of low life time of electrolysis cells.


 

2015


Cold-ramming paste.


RUSAL, Krasnoyarsk performed laboratory tests of MHNP cold-ramming bottom paste manufactured by PJSC "Ukrgrafit". The results have satisfied RUSAL requirements, operational tests, two railcars with MHNP paste at Krasnoyarsk and Sayanogorsk aluminium plants are being carried on.


 


Within 2013-2015, in comparison with the preceding periods, PJSC "Ukrgrafit" has built up production volumes and sales of cold-ramming pastes for use in blast and other metallurgical furnaces.


Consistently high quality of the  product made it possible to obtain such results and, as a consequence, long-term contracts with consumers from Ukraine, Kazakhstan and the EU countries were concluded.


 


Materials for the furnace lining.


In 2015,  the central research laboratory  at PJSC "Ukrgrafit" manufactured samples of carbon blocks for the lining of metallurgical furnaces with additives which improve resistance of the material to penetration of liquid melted products. The above work was  performed with the purpose of increasing the service time of the lining in the most stressed areas, for example,  tap hole areas of blast  and ferroalloy furnaces. At present search for proper  methods of assessments of resistance of the carbon block samples in industrial conditions.


 


Anodes for the magnesium industry.


In 2015,  within a special program of development we continued testing of new anodes out of bars with increased dimensions: up to 2921 mm long, up to 703 mm wide and with thickness of up to 250 mm, and also glued "standard" top  (AV) and bottom (AN) mounted anodes with various widths out of  separate anode bars.


 


Glued anodes:


Trial industrial tests of AN anodes glued out of  two bars of AN and AV anodes  (with protective impregnation against oxidation) are carried out.


 


Monoanodes - are  anodes consisting of one large-sized bar:


Trial industrial consignments of AN and AV anodes (with protective impregnation against  oxidation) out of  bars of BN grade are being tested by foreign consumers.


 


Large-sized graphite bars.


We are developing manufacturing of anode large-sized bars of BN, BV and BMV grades for manufacturing of  AV and AN anodes. Within  joint programs with consumers we are testing in industrial conditions  the anodes manufactured out of those bars, including:


- AV and AN up to 1650 mm wide  out of  BN, BV and BMV bars up to 660 mm wide.


 


Preparation for production of advanced products: 


The process was developed and semifinished products for the consequent manufacturing of trial ВN anode bars with dimensions 183х686х2921 mm, 183х457х2921 mm, 250х600х2420 mm, 60х703х1250 mm and 60х691х1250 mm designed for advanced electrolysis cells on the existing and new markets.


 

2014


Graphite electrodes for ultra high power steel furnaces.


In 2014,  we started manufacturing of EGSP Ø650 mm graphite electrodes for which a  new die was manufactured. Also a recipe was found,  using which  good  well-formed electrodes were  produced at the first attempt.


The above electrodes are intended for large UHP steel furnaces (over 150 mt of  metal in one heat).


In 2014,  Dneprostal, Dnepropetrovsk  successfully tested EGSP (UHP) electrodes  Ø 650 mm 2700 mm long. Those electrodes performed similarly to  European analogues (UCAR, SGL Carbon).


 


Bottom blocks with the increased resistance to abrasive wear.


In 2014, the technology for graphitized bottom blocks with the increased resistance to the abrasive wear was developed and a trial lot of blocks was manufactured. Assessment of the abrasive wear of blocks was performed in an independent laboratory (R&D, Switzerland). The resistance to the abrasive wear of the trial lot of the graphitized bottom blocks is 44,5 %  higher than that of the blocks manufactured with the use of the common technology.


 


Cathode products.


In order to satisfy the requirements of consumers and to expand the sales market of cathode products,  in 2014, independent laboratory of ELTER Scientific and technical center  carried out high-temperature test (20-1000ºС)  of PB3, PB10, PBG, PBG-2 bottom blocks. Test results confirm conformity of the characteristics of the products with the consumers' expectations.


Anodes for the magnesium industry.


In 2014, within the programs of development fine-tuning of the technology, manufacturing and testing of standard and trial anodes out of  bars with increased dimensions up to 2921 mm long, up to 703 mm wide and up to 250 mm thick, and also glueing of "standard" anodes having various widths out of  separate anode bars.


 

 

Efficient operation of the enterprise is impossible without introduction of the latest technologies and modern process equipment, without development of new carbon of materials and expansion of the range of products, without constant increase of technological level and quality of fabricated products.

Over the last few years a lot of work has been done to improve products and manufacturing processes, a lot of programs and projects have been implemented. 

High-efficiency screening units of new generation ensuring high purity of useful fractions of raw materials during their processing; automated control systems for classification, mixing and extrusion in a mixing and pressing workshop; an apparatus for monitoring bulk density of blanks by hydrostatic weighing have been introduced. 

The systems of vacuum degassing of moulding mix during the moulding of raw materials on the graphite production line, and also a special modern baking furnace with automated system of running the process have been introduced. The line for machining large-sized electrodes (400 mm and over ) with capability of machining of blanks up to 3000 mm long has been modernized. For updating the graphitization technology the 3-d mathematical model of temperature fields of the graphitization furnace has been developed and introduced which will allow achieving optimization of the manufacturing process and improving technical and economic indicators of the graphitization workshop.

High-efficiency high-speed EIRICH mixer (including dosing units for auxiliary materials, preheater for the working mixture, high-speed mixer with cooling system and conveyors for supply of paste to presses) on the carbon and graphite product production line, efficient and precision automated Wassmer line for machining of cathode blocks have been put into operation.

A test ground for dry test preassembly of the elements of the lining has been modernized, which allows test preassembly of carbon linings for any existing designs of industrial furnaces. 

Modernization and specialization of baking furnaces No.7 and No.10 in workshop No.3 which made it possible to lower the consumption of natural gas by 30 % and improve baking due to minimum temperature differences at the height of the material to be baked has been carried out 

Technologies have been developed and production of new types and grades of products for the lining of metallurgical furnaces, anodes and cathodes for aluminium and magnesium industry, electrodes and electrode pastes for steel and ferroalloy industry, and also other electrical thermal productions has started

At present PJSC «Ukrgrafit» has large technological and intellectual potential, there is a team of professional managers and experts, the enterprise is equipped with modern research equipment such as: NETZSCH dilatometer, EIRICH mixer, apparatus for determination of bulk density and thermal conductivity of loose materials, Brookfield viscosimeter etc.. The metrological base of the enterprise has been re-equipped and today we have up-to-date measurement tools, control and measurement instruments, systems of marketing research, development of new types of products and launching of technology of their production at the enterprise have been created. 

Today everything is ready for implementation of the projects and planned programs. In the near future according to the plans of the enterprise the following will be done:
• construction of new up-to-date lines for machining electrodes achieving high purity and accuracy of machining of the products;
• improvement of the existing graphitization technology and also expansion of production and introduction of up-to-date lengthwise graphitization facilities;
• improvement of anode paste production with application of up-to-date equipment and automated systems;
• implementation of technology and starting production of new grades and types of products to satisfy the present and future demands of traditional consumers of carbon and graphite products.

At present PJSC «Ukrgrafit» has far-going ideas in the field of improvement of commercially produced products, and in the field of creation of new kinds of products focused on the future requirements of consumers, expansion of the range of application of materials and products based on carbon. 

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