Production

Competitive advantages of SkyWay cargo transport complex for transportation of rock mass

Expenses on transport are one of the most essential component of the total costs of extraction and processing of commercial minerals. This proves the need to justify the use of the most effective complex of transportation. However, a complete and comprehensive analysis of optimal transport complex is often not carried out. The preference of one or another mode of transport is determined mainly by a subjective opinion.

Currently, mining companies apply mainly the following competing technological transport systems: railway, suspended air-cable ways, conveyors and motor-road transport.

The main factors having the greatest influence on the choice of a transport complex for the mining business are:

  • terrain and other specific features of construction area (ecological aspects, housing development, availability of natural and artificial water bodies, etc.);
  • transportation distance;
  • haulage volumes and type of cargo;
  • the need for staff;
  • capital expenses;
  • operational expenses.

As practice shows, cable-belt conveyors have, in most cases, the lowest total cost (capital expenses and operating expenditures for the entire period of operation) for transportation of bulky materials over long distances (above 10 km). The table below shows the main technical characteristics of some of the world's largest cable-belt conveyors. For comparison there are also data for the variant of applying SkyWay cargo complex with the capacity of 65 million tons per year (2.15 tons per day), unattainable for the competing transport systems.

The most important are [1]:

  • the parameter that determines specific energy consumption for haulage of rock mass Eec, kW×h/t×km:

where

N – installed power, kW;

L – distance of transport system, km;

Pproductive capacity of transport system, t/h.

  • net cost of cargo transportation Сen (without depreciation expenses), cent/t×km:

Cen = Eec × СkW×h = 25 × Euc,

where

СkW×h = 25 cents – cost of power for 1 kW×h.

Table

Comparison of the main technical characteristics of some of the world's largest cable-belt conveyors and  SkyWay cargo transport system

Customer

Location

Distance L, km

Productive capacity P, t/h

Product

Velocity V, m/s

Installed power N, kW

Annual productive capacity Py, mln ton

Specific energy consumption Eec, kW×h/t×km

Net cost of rock mass transportation at cost of power for 1 kW×h = USD 0.25 Cen, cent

Peabody Energy

USA

14,598

1360

coal

4,19

1865

11,4

0,094

2,3

Anamax Mining Company

USA

9,913

2000

copper ore

4,19

1865

16,8

0,094

2,4

Electricity Comm NSW

Australia

10,4

2500

coal

4

2500

21,0

0,096

2,4

Worsley Alumina

Australia

30,441

2300

bauxite

6

8000

19,3

0,114

2,9

Worsley Alumina

Australia

20,712

2300

bauxite

6

5200

19,3

0,109

2,7

Alpart

Jamaica

14,192

1428

bauxite

4

1865

12,0

0,092

2,3

SkyWay cargo transport system

10,0

7738

ore, coal

8

1800

65,0

0,023

0,6

Railroad transport system

-

-

-

-

-

-

-

4,7

Net cost of rock mass transportation at cost of power for 1 kW×h = 25 cents

As the table shows, for the specified conveyor transport systems of overpass type (with the account of slight inclines on the route) calculated parameters are within the following ranges:

Eec = 0.092 – 0.114 kW × h/(t × km),

Cen = 2.3 – 2.9 kW × h/(t × km)

 

For example, for railroad transport as an alternative transport system, the index is:

 Cen = 4.7 – 7.5 cent/t × km

SkyWay cargo transport complex is a product line of overpass type, intended for transfer of bulk cargo (transportation volume is up to 250 million tons/year).
The overpass of the transport complex is a pre-stressed spatial truss structure mounted on supports above the ground. The height of the supports is such that it allows to pass freely over the existing buildings, highways, power lines, communications and other service lines.

On the overpass there is an operational rail-string track designed for a long unicar train, transporting bulk cargo with a total capacity of up to 100 thousand tons. To service the cargo transport complex and perform technological operations, there is a technological-maintenance rail vehicle travelling along a separate line, combined with the operating track.

The use of a rail-string technology and selection of optimal design parameters allowed engineers of the SkyWay Technologies Co. to reduce the specific resistance to the movement of cargo rolling stock and reach values of specific energy consumption on Сen to the level of 0.023 kW×h/t×km (taking into account slight inclines on the route of up to 3%). It also made possible to reduce the cost of haulage to 0.6 cents/t×km, which is 4−5 times less in comparison with alternative transport systems and 8−12 times less in comparison with railroad transport.

In addition, there is a huge potential in the operation of the complex in highlands. For example, if transportation occurs from a mountainous region to a seacoast or to an area located lower than the mining site, on the 500 km route distance sufficient is a total altitude difference of 1,500 meters for the complex not to consume electricity for ore transportation at all. Using regenerated potential energy of cargo descent from the mountains, SkyWay cargo transport complex will be able to exist completely autonomously, that is particularly important for undeveloped regions of the planet. The total cost of haulage by such a system would be even lower than that of the same system for flat terrain due to lack of electricity expenses.

The transport structure of the complex can be used to align high-voltage power lines, solar panels, communication lines, to arrange wind power plants on the supports.

An important aspect is lack of environmental problems arising from the construction and operation of SkyWay cargo complex. For example, while constructing a railway embankment, the natural hydrology of the area is changing, since, in fact, such embankment becomes a low-pressure dam, which acts as an artificial watershed. A significant problem is the railroad crossing of migration routes of animals that are dying in large numbers under the wheels of locomotives.

Fertile agricultural lands are withheld from cultivation for the construction of railway networks.

Cargo SkyWay transport system has none of these problems: the transport overpass is located at a height of 5−8 meters above the ground, supports are installed in every 40−50 meters and the area of land allocated for one intermediate support, does not exceed 2 square meters. Thus, 1 kilometer of route needs withdrawal of not more than 100 square meters of land with the account of anchor supports (which occupy up to 50 m2/km). Assembling of a transport overpass implies minimum manned  technology; loading and unloading of rolling stock is done in motion, without stopping; the track is of all-weather type and has a great durability due to small loads on wheel shafts and the overpass. These technical and technological solutions have been tested on the experimental section of the track in the town of Ozyory, Moscow region [3].

Lack of environmental problems during the construction of the transport system is a significant advantage, because the number of nature-preserving measures (and, respectively, funds for their implementation) in this case is minimal. For example, the initial project cost of the gas pipeline in Alaska (USA) amounted to USD 600 million, but after protests from community and environmental organizations its construction was blocked. Then, after the implementation of all nature-preserving measures, which is particularly expensive in permafrost conditions, the pipeline was built, but its cost rose to USD 5 billion, i.e. 8 times more expensive.

There are known cases when large mining projects have been closed since the construction of a railway to the port did not pass ecological expert examination.

SkyWay cargo transport is a breakthrough in the field of bulk cargo haulage; it provides the opportunity to develop such deposits, which are uneconomical or impossible for development with the use of conventional modes of transport: in mountainous areas, nature conservancy zones, in tundra and the jungles. SkyWay technologies allow the transport to move on the gradient of up to 40% – and this means that the system is flexible, the overpass literally repeats the profile of the terrain, and the cost of track structure increases by only 25−30 % compared with the option for flat terrain.

The cost of SkyWay transport complex depends on many factors: traffic volume, country of implementation, terrain, natural, climatic and other conditions. The average cost of rolling stock, overpass, terminals and infrastructure, referred to 1 km length of the route, is equal to: for plain terrain − from USD 1.5 million/km, for rough terrain – from USD 2 million/km, for mountainous areas – from USD 2.5 million/km. For comparison: in Australian conditions a single-track cargo railway costs for the customer in the amount of USD 5 million/km.

With the appearance of SkyWay technologies, ore mining in many mountainous regions can become profitable. Even in ideal conditions for the  existing transport systems, cargo SkyWay transport complex requires less operating expenses by 4−5 times at the same productive capacity, which will allow to save hundreds of millions, and even billions of dollars a year*. For mountainous conditions, cargo SkyWay transport system will significantly increase the profit compared to a conventional cable-belt conveyors, not to mention conventional railway transport, which in these conditions simply do not stand up to any competition. For example, the allowable longitudinal gradient of 0.9% makes railway men to pass through mountains and build tunnels, bridges and viaducts with enormous spans, designed for a giant load. It increases the railroad construction cost   in a mountainous area by at least 2.5 times, and often makes the development of minefields unprofitable. In case of pessimistic prices, ore mining in mountainous areas becomes unprofitable when using railway transport, while, using SkyWay technology, profit remains at rather a high level. This feature provides for a company, using SkyWay transport technologies, not only the possibility to thrive in times, difficult for all others, but also to use this "economic weapon" to fight with competitors, achieving a complete monopolization of the industry in some aspects.

References:

  1. Journal "Mining industry" No. 3, 2005, article "Cable-belt conveyors of great length", authors: Andrew Lewis, General Manager, production line "Bulk material transportation" of Metso Minerals (UK) Ltd., England; L. Grebeneshnikov, marketing Director (wear protection and conveyors), "Metso minerals RUS CO", Russia. (in Russian)
  2. Journal "Mining Industry" No. 2, 2012, p. 96, article "Modern systems of transporting minerals and overburden rocks", authors: A. A. Tverdov, Ph. D., IEEC mining engineer; A. V. Jura, Ph. D., IEEC consultant on economics and marketing, S. B. Nikishichev, Ph. D., Director of the IEEC. (in Russian)
  3. Rational use of natural resources: resource and energy saving technologies and their metrological support / Materials of international scientific-practical conference, 22-24 June 2004, Petrozavodsk. – Moscow: Federal State unitary enterprise "VIMI", 2004. – 385 pages; pp. 98 – 100, article "String transport system – transport of the XXI century", author: A. E. Yunitskiy. (in Russian)

* For example, at the distance of 500 km transportation, a mining company that has a traffic volume of 65 million tons per year, will save (earn) on transportation of ore, as compared with the railroad: (0.047-0.006)×500×65000000=1,332.5 million USD per year. However, during the service life of the SkyWay system (50 years) savings will exceed USD 60 billion.