FEASIBILITY STUDY OF BASIC TECHNICAL SOLUTIONS OF TRANSPORT OF TAILINGS IN EXAMPLE OF CHERNOGORSKOE MINERAL DEPOSIT

Zavertkin Pavel, project manager, Ph.D., JSC “PiterGORproject”

Zavertkin Mikhail, process engineer, M.Sc., JSC “Rusal VAMI”

The article describes the evaluation of the various options for transporting of tailings in the development of the Chernogorskoe copper-nickel ores. It includes a comparative analysis of the options for the minimum criteria discounted costs.

Introduction. Basic methodological position

This paper presents the feasibility study of basic technical solutions of tailings transporting in conditions of Chernogorskoe deposits of Krasnoyarsk region (Russia). Initial data for estimation is an average annual volume of tailings 6912 tons with 20% humidity. Estimation is performed for the process of transportation and laying of dry tailings.

The purpose of the paper is to compare 3 variants:

Option 1 - road transportation (Dump trucks 30 tons);

Option 2 - conveyor transportation using a tubular pipe;

Option 2a - transportation conveyor using classical conveyor belt

Transportation of tailings is done by dump trucks from concentration plant to warehouse dry tailings. Formation of a warehouse of dumps is done using dozers. Handling of dry tailings is a front loader type CAT 988N with a bucket capacity of 6.4 m ^3. Transportation capacity is 30t dump trucks such as Scania 380SV.

For the scheduled amount of work on the loading must use two types of loader CAT 998N with an annual output 1700 000 m³.^.

Initial data for the calculation are shown in the table (Table 1).

Work schedule is shown in the table (Table 2).

Table 1. Initial data for estimation

Number N / N	Index	Title	Unit of measurement	Value
1	Annual traffic	Q	m3	3285
2	Annual traffic	Q	tonnes	6912
3	Volume weight in the transport vessel	γ t	t / m ^3	1.8
4	Bucket Loader	V	m ^3	6.4
5	Cycle time loaders	t n	min	0.8
6	Dumping time	t p	min	2
7	Maneuvers	t m	min	2
8	Speed laden pos.	v g	km / h	20
9	Speed in empty pos.	v has	km / h	30
10	Number of shifts per year	n cm	cm	730
11	Duration of change	t cm	hour	12
12	Coeff. Those ready	k t		0.76
13	Coeff. Fleet utilization	k and		0.9

Table 2. Schedule shipment and storage of dry tailings

Figure 1. Schematic of the formation of dump

For all options there are examined four specific periods, depending on the form dry tailings storage time (increased area of the warehouse and capacity stacking stages see Figure 1):

Option 1

Phase 1 – from 1-6 years. Transportation by road is a distance - 2.4 km;

Phase 2 - from 7-12 years. transportation by road is a distance - 2.7 km;

Phase 3 - from 13-18 years. transportation by road is a distance - 3, 3 km;

Phase 4 - from 19-23 years. transportation by road is a distance - 3, 7 km.

Option 2 and 2a

Phase 1 - from 1-6 years. Transportation conveyor transport is at a distance - 0, 6 km;

Phase 2 - from 7-12 a distance - 1, 0 km;

Phase 3 - from 13-18 years. Transport conveyor belts is the distance - 1, 4 km;

Phase 4 - from 19-23 years. Transportation conveyor transport is at a distance - 1.6 km.

The main criterion for the evaluation and selection of options is a minimum discounted cost.

For comparison, the company adopted the discounted costs for transportation tailings.

,

where:

Ct – cash costs of enterprises in period t,

Kt - investment in period t,

dt - the discount factor.

Discount factor is determined for each period to formula:

,

where: E - the discount rate.

Cash costs are determined for each year of the settlement period t.

Discounted costs of enterprises C^d are calculated for each case separately:

for 1 option - discounted cash expenditures of the enterprise are the sum of operating costs for transportation and laying in dry tailings only on the distance from the processing plant to the warehouse dry tailings and capital expenditure for the purchase of fleet of dump trucks and equipment;

for 2 and 2a s option - discounted cash expenditures of the company consist of the costs on a conveyor transporting and stacking of spreader dry tailings and the capital cost of installation conveyor-dumping complex.

Production costs

Cash costs of enterprise C^t include all the necessary articles for transportation costs (salaries with compensation and social security contributions, material resources, energy and others. (See Application).

Capital investments

Calculations for capital investments are made in the national currency (rubles) in the current price level II quarter 2013

Cost of equipment adopted in the current price level II quarter of 2013 based on data from manufacturers and supplier companies operating in the market of the Russian Federation with regard to transport and harvesting and storage costs, as well as customs duties for import of equipment.

Counter sinking stream.

The funds earmarked for depreciation, and match as income, cause of decrease overall costs and significantly improve the performance of capital conveyor options.

Conclusions

Indicator analysis identify the benefits of the resulting table option 2A pipeline transportation using the classic conveyor belt. Costs for this option 20% lower than for Option 1, thus 1,75 billion rub. against 2,10 billion rub.in accordance of E = 10% (please see Table 3).

Also adjusted cost for option 2a 13 5% lower than for Option 2 - 1, 7 5 billion rub. against 4.11 billion rub. at E = 10%.

However, technological comparison of all three variants makes strong arguments in favor of any of them. Pipe conveyor option completely eliminates dusting during transport, but the probability of sputtering at the expected moisture content of 20% is quite low.

Bibliography

1. Report on the results of exploration of the Chernogorskoe copper-nickel deposit with reserves estimated as at 01.01.10 "Exploration (additional exploration) Chernogorskoe copper-nickel ores in 2006-2008."

2. Holt, Barnes. Sat Investment planning: Per. from English. M. Case Co., Ltd., 2009

3. Tsarev Vladimir. Assess the cost effectiveness of investments. St. Petersburg: Peter, 2004

Application

FINAL PERFORMANCE COMPARISON

Total discounted costs of transportation options for tailings (by changing factors for the entire evaluation period)

Table 3.

Name of indicators (million).	Option 1 with road transportation of	Option 2 with conveyor transportation of the application of pipe conveyor	Option 2a with conveyor transportation of the application of the classical belt
Operating cash flow
Production costs:	4929.36	5482.59	2 648,29
including:
Operational (operating expenses, excluding depreciation)	4421.29	3 323,59	1 850,86
Depreciation deductions	508.07	2 159,00	797.43
Property tax - 2.2% of the net book value of fixed assets	64.57	530.28	200.78
Total outflows of operating cash flow, taking into account the property tax	4993.93	6012.87	2849.07
Investment flows
Capital expenditures, total	278.69	2 653,86	1032.01
Capital investments for equipment replacement	259.13	0.00	0.00
Flow from investing activities	537.82	2 653,86	1 032.01
The balance of the two flows (production cost + property tax + investment costs, including the amortization of counter flow)	5023.68	6507.74	3083.65
Given the discounted costs (including depreciation counter flow) at a rate of discount:
0%	5023.68	6507.74	3083.65
10%	2095.3	4110.84	1747.90
15%	1570.83	3674.92	1507.54

Key words: feasibility study, belt conveyer, truck transport, dump, mineral deposit