Study on technological solutions and management for sustainable developments of building stone mines in vietnam

MINISTRY OF EDUCATION AND TRAINING
UNIVERSITY OF MINING AND GEOLOGY

HOANG CAO PHUONG

STUDY ON TECHNOLOGICAL SOLUTIONS
AND MANAGEMENT FOR SUSTAINABLE
DEVELOPMENTS OF BUILDING STONE MINES
IN VIETNAM

Specialized: Mining
Code: 62.52.06.03

SUMMARY OF ENGINEERING DOCTORAL THESIS

HANOI - 2016


The thesis is completed at:
Department of open pit mining, Faculty of mine,
University of Mining and Geology

Scientific supervisors:
1. Prof. Dr. Tran Manh Xuan
Vietnam Mining Science and Technology Association

2. Dr. Nguyen Phu Vu
Vietnam Mining Science and Technology Association

Reviewer 1: Prof. Dr. Nhu Van Bach
Vietnam Blasting Engineering Association

Reviewer 2: Ass. Prof. Dr. Bui Xuan Nam
University of Mining and Geology
Reviewer 3: Dr. Lai Hong Thanh
General Department of Geology and Mineral of Vietnam

The doctoral dissertation defense will be made before the Thesis
Examiner Council of the University of Mining and Geology, Duc Thang
Ward - North Tu Liem District - Hanoi.
At ....... ...... date ......month ..... year 2016
The thesis can be referred at:
- National Library, Hanoi;
- Library of University of Mining and Geology


PREAMBLE
1. Rationale
Vietnam possesses abundant mineral resources across the country for
construction materials. As such, the industry of mineral exploitation for
construction materials is strongly developed to meet the needs of
industrialization and modernization of the country.
Minerals used for construction vary widely, including rock, sand and soil;
among these, building stone have the highest proportion in both quantities of
mines, output, value as well as the amount of workforce involved in the
production stage. Exploitation scales of the mines, especially stone mines, are
also varied, ranging from tens of thousands to millions of cubic meters per year.
Exploitation technologies applied may be manual, semi-mechanized, fully
mechanized at different levels.
This industry has provided construction materials for economic
development of the country. It creates jobs for thousands of workers and
significantly contributes to the national budget. However, it also has many

drawbacks associating with security, rational use of resources and
environmental protection. Reasons for these drawbacks include outdated mining
techniques, especially in quarrying and insufficient licensing in some localities.
Therefore, the research is necessary and can contribute to the sustainable
development of the mining sector for construction materials of the country.
2. The purpose of the study
- The research proposes solutions in stone mining for construction
materials to improve production efficiency, safety, environmental protection
and resource recovery. Based on classification of mines according to terrain
conditions and sizes, the research studies the ability to apply the suitable system
of exploitation (SE).
- The research proposes solutions to improve management, specifically
about mining licensing, mine networks under planning; encourage the mining
sector for construction materials to apply advanced techniques to enhance
production efficiency.
3. Object and scope of the research
- Stone mines for conventional construction materials and for cement production.
- Particularly in the section of technological solutions, the research is only
focused on the mines locating above the level of gravity drainage.
4. Subject’s matters
- Overview of the exploitation and management of stone mining in the
country as well as experience in the world.
- Classification of mines by the terrain conditions and sizes. Classification
of SE of the mines by features that match the mining technology; analysis of
applicability and conditions.
1


- Construction of technological schemes, calculation of parameters for SE,
orders of exploitation, the capability between opening and exploitation for each

type of classified mine.
- Establish criteria for mining licensing mechanism and innovative
solutions for technical management and mine administration.
5. The scientific and practical significance
- Scientific significance: improving the theory of open-pit mining for
stone mines in complex and fragmented terrain conditions where various
technologies need to be applied within the same mine; improving mining
licensing model and management of stone mines.
- Practical significance: the research serves as the scientific basis for state
management agencies and enterprises to refer and apply comprehensive
technology and management, to facilitate the stone mining sector to apply
advanced technology into production; to ensure safety and rational use of
mineral resources as well as environmental protection.
6. Arguments
- The selection of appropriate mining technologies or application of
technical solutions must take into account the type of mine classified based on
terrain conditions and mine size. The SE classification also needs to add more
details about the characteristics of the production stages on mine.
- Management must rely on scientific-based economical and technical
criteria and current operations as well as the development trend in the future.
- The improvement of mining technologies as well as the innovation of
management mechanism to encourage enterprises to apply advanced mining
techniques for production efficiency, safety and environmental protection is the
precedence for a sustainable stone mining sector.
7. Innovative aspects of the thesis
- Propose a mine classification method according to terrain conditions and
mine size, classify stone mining SE as a basis for the selection of mining
technologies or improving appropriate exploitation techniques.
- Propose a calculation method for parameters of SE, method of benches
preparation, mining order when various techniques are applied.

- Propose scientific-based criteria for licensing; manage stone mining
sector based on planning, merge adjacent small mines into larger mines to
enhance financial capability for more advanced technology; build selfgovernance regulations based on the "Self-test" sheet.
8. Layout of the thesis
Besides the introduction and conclusion, the thesis consists of more than
150 pages, numerous tables and figures and references from Vietnam and other
countries:
Chapter 1. Overview of mining technology and the management of
building stone mines in Vietnam and experience of stone mining in the world.
2


Chapter 2. Analysis of the factors affecting the sustainable development
of building stone mining in Vietnam.
Chapter 3. Research on the technological solutions to ensure the
sustainable development of building stone mining in Vietnam.
Chapter 4. Research on management solutions to ensure the sustainable
development of building stone mining in Vietnam
9. Publications
According to the research direction, 14 papers and/or abstracts have been
published in magazines of mining, domestic and foreign conferences.
CHAPTER 1
OVERVIEW OF MINING TECHNOLOGY AND
MANAGEMENT OF BUILDING STONE MINES IN VIETNAM AND
EXPERIENCE OF BUILDING STONE MINING IN THE WORLD
1.1. Overview of potential and distribution of building stone in Vietnam
Vietnam possesses abundant sources of rocks for construction materials
across the country. According to incomplete statistics, reserve of cement
limestone in Vietnam is about 44.7 billion tons and reserve of rocks for
conventional construction materials is about 53.6 billion tons (Table 1.1).

Table 1.1. Building stone reserves in Vietnam
T
T

1

2

3

Region /
Type of
Mineral
Cement
limestone
Number of
mines
Million
tons
Paving
stone
Number of
mines
Million m3
Building
Stone
Number of
mines
Million m3

Northern
highland

Red river
delta

North
Central
Coast,
Central
Coast

Central
Highlands

South
East

Mekong
Delta

Total

157

83

82

1

6

22

351

21,869.800

9,681.210

12,018.352

23,468

569,884

575,770

44,738.484

90

12

205

55

40

8

410

5,188.860

59.330

25,213.393

580.680

1,319.976

5,228.000

37,590.239

98

66

167

84

129

20

564

2,947.260

2,673.760

42,595.890

1,699.150

3,284.590

408.260

53,608.910

3


1.2. The situation of production and consumption of stone
The abundant stone resource has met the raw material demand for cement
production with increasing output: 67 million tons in 2010, 72 million tons in
2014, and expected 112 million tons by 2020. The output for building stone
reached 110 million cubic meters in 2010, 115 million cubic meters in 2014 and
is expected to reach 226 million cubic meters by 2020 (Table 1.4).
Table 1.4. Statistics and forecasts of demand for building stone and cement stone
Category

Unit

Building million m3
stone
Cement Million tons
stone
Paving Million m2
stone

2010
2015
2020
Demand Output Demand Output Demand Output
115

104

164

148

226

204

65.59

59.02

99.5

88.5

> 112

112

11.5

8

16.3

14

25

20

1.3. Overview of the mining technology of building stone mines in Vietnam
Currently, there are 351 mines for cement production, 564 mines for
conventional construction. There are various technology applications being
applied and can be grouped into 4 following categories:
1.3.1. Mining in vertical slicing, conveying by blasting (non-standard mining
or free mining)
This is a non-leveling, non-standard mining method, which used drilling
and blasting to remove rock from the blocks on the inclined plane to toe of
slope. This technology is applied mainly for conventional building stone mining
and small scaled cements stone mining. The method is currently applied for
many mines in the North including Ninh Binh, Ha Nam, Hai Duong, Hai
Phong, Thai Nguyen, Lang Son, etc. The hammer small-diameter drill ( = 32 45mm), shoveling by bucket excavator with a capacity E ≤ 0.5m3 and truck

with load of 5-7 tons are applied in most of the mines.
Advantage: This is a simple mining technology, low investment, cheap
cost and suitable for small-scale mining companies with limited financial
conditions; the requirement for mining area is not large.
Disadvantage: This mining technology is an unsafe; causes wasteful and
loosed resources; potentially high environmental pollution and easily leading to
the situation of only mining the easy parts while giving up the difficult ones.
1.3.2. Mining in horizontal leveling and conveying by truck
This technology is applied mainly to limestone mining for cement production.
4


This technology is mainly applied to stone mining of the lower part of the
mountain after initial top cut: Yen Duyen (Thanh Hoa), Ang Dau, Ang Son
(Hai Duong), etc. mines. The mining equipments using in these mines are very
diversity, of which the drill rig with drilling diameter of  = 105 - 200mm,
bucket excavator with capacity of bucket E = 1.2 - 1,8m3, truck with load of 1015 tons and height of slice h = 10 - 15m are very popular.
Advantage: High mechanized ability; safe operation, can exploit
selectively, low environmental pollution.
Disadvantage: Great investment capital, long time of mine preparing,
expensive cost.
1.3.3. Mining in vertical slicing and conveying by bucket excavator and truck
This technology is applied for some following mines: Thong Nhat (Hai
Duong), Hoa Thach Lien (Hanoi), Dong Tram Hoa (Ha Nam), Tien Hoa
(Quang Binh), etc. The mining equipments included drill rig with drilling
diameter of  = 105mm, bulldozer with capacity of 130 - 240CV, excavator
with bucket capacity of E = 0.8 - 1,6m3 and truck with load of 15 tons are used.
The height of slice is less than 7 meters; the cut width is less 10 meters.
Advantage: This is a simple mining operation technology, which can be
applied for Stone Mountain with heavy pitch.

Disvantage: The application is restricted in case of large volumes,
requires large, long working platform, causes huge amount of dust during
shoveling and transporting stone to mountainside or pit slope.
1.3.4. Mixed mining technology
This technology is as follows: The upper part of the mountain is mined in
horizontal slicing using hydraulic drill rig with drilling diameter of 64 - 130mm
and shoveled by bucket excavator with capacity of E = 4-6m3, or using bulldozer
with capacity of 130 - 420CV. The stones are shoveled from working platform at
the toe slope using bucket excavator with capacity of E = 3.5 - 4,6m3 and
transported by truck with loading capacity of 27-40 tons. The lower part of the
mountain is mined in horizontal slicing, and then transported by truck.
This mining technology is applied quite popularly in some mines: Trang
Kenh (Hai Phong), Minh Tan (Hai Duong), But Son, Hong Son (Ha Nam), Yen
Duyen (Thanh Hoa), Hang Nuoc (Ninh Binh), Hoang Mai A mine (Thanh
Hoa), etc.
Advantage: Capable of full mechanization of production in mines, can
increase yields while exploiting the lower and selective, safe shoveling.
Disadvantage: complex mining operation, causing huge amount of dust
during shoveling or shifting.
1.4. Some experience in building stone exploitation in foreign countries
As with Vietnam, other countries must counter difficulty in mines in
mountainous areas due to the complex terrain and it is impossible or too
expensive to make trenches from the ground up to the mining slices for
5


transportation of stone. Therefore, stone transportation using gravity combined
with other forms is applied to reduce the distance and costs during exploitation.
Accordingly, seams may be opened by wells or pits, taking advantage of gravity
to transport rocks down from the height.

It is shown from foreign literatures that seam opening of the working slices
in underground mining for transportation by gravity is reasonable if the slope is
greater than 200. Wells can be used to transport rocks in open pit mines with
output of 4-5 million tons/year, while the use of chutes achieves lower output.
In addition to plans for "hopper – vertical shaft and transport by narrow
rail haulage in tunnel mining" was applied in the early stages, today many
countries apply a relatively modern exploitation technology combining "gravity
- conveyor" with crusher located at the bottom of the well (the UK, Australia,
Japan, Switzerland, etc.).
This technology is applied in mines that operate in vertical slicing with
car or loading machine as transportation vehicles and height of bench is usually
15m. Devices are synchronized and advanced: hydraulic drill with diameters
from 80 - 203mm, loading machine with bucket capacity of 5 - 20m3, excavator
with bucket capacity of 5 - 7,5m3, and truck with load of 40-80 tons.
Mining technology with stones being conveyed by bulldozers on
horizontal or inclined surface is also applied in several mines in Spain,
Germany and Algeria.
1.5. The current status of the management of the building stone mines
1.5.1. Current status of mine licensing and land leasing, and some issues
Mine licensing and land leasing for mining in Vietnam can be described
by the following diagram (Figure 1.9):

Figure 1.9. Mine licensing and land leasing model
6


In some localities, mine licensing still has the nature of “asking and
giving”, is not scientific and practical based, creating red tapes for the
enterprises, leading to fragmentation, unsafe mining, overlapping, waste of
resources and environmental destruction. There has been lack of consensus

between mining licensing bodies and land leasing agencies.
1.5.2. Inspection
In recent times, the inspection work lacks the coordination between
central and local agencies; the inspection work is still considered largely an
administrative task.
1.6. Analysis of the related studies
There have not been many studies in technology of building stone mining
in our country. The vice doctoral thesis of Nguyen Thanh Tuan (1985) is among
the best known work in this field. There are also 02 technical master thesis of
Le Thi Thu Hoa (1998) and Nguyen Minh Huan (1999). Besides, there are
some other studies for curriculum or reference books by such authors as Tran
Manh Xuan, Ho Si Giao, Bui Xuan Nam, etc.
The previous studies have not suggested the appropriate technological
scheme for stone mining in different terrain conditions and sizes or analysis of
application field for each type of ES; there is no research on improving the state
management on the stone mining for construction materials.
CONCLUSION OF CHAPTER
Currently in Vietnam, most mines use outdated technology, especially
small-scaled mines and stone mines for conventional construction materials.
The outdated technology applications lead to waste of resources, environmental
destruction, pollution and low economic efficiency.
The main reason is that suitable technology applications are yet to be
found. Management of mining operations is inadequate.
CHAPTER II
ANALYSIS OF FACTORS AFFECTING THE SUSTAINABLE
DEVELOPMENT OF BUILDING STONE MINING IN VIETNAM
2.1. Management factor
2.1.1. Mine licensing
An efficient open-pit stone mine needs 02 following conditions:
- Proper area for normal operation,

- Life span of mine longer than payback time.
If mine licensing is only based on the reserve and exploitation duration
without the consideration of the area of mine, the application of technology for
efficient operation is difficult.
2.1.2. Method of reserve calculation to pay for mining rights
Mineral reserve used as a basis to pay for the mining rights is calculated
by vertical section and depth of mine floor, which leads to the difference
7


between calculated reserve as regulated and the actual reserve due to the
presence of mine banks. This causes economic losses for mining enterprises,
and the extent of loss depends on the depth and angle of the bank.
In addition, the application of the same expansion coefficient for all
mines is not rational.
2.1.3. Inspection
There lacks of coordination among agencies regarding inspection of
mines, and the reporting and information management is still inefficient. A
system of specialized inspection agencies from central to local has not been
formed, which leads to the inefficient management and adversely affects the
capacity to take full control of the business activities in accordance with the
criteria set out.
2.2. Mining technology
Mining technology is important in the sustainable development of the
stone mining industry. Therefore, it is necessary to conduct research and
classify mines by terrain conditions and sizes; classify the ES and its applying
conditions; add and define the parameters needed in the design and production
process; apply the technology that is flexible to work in complex terrain
conditions, taking into account the investment capacity of businesses.
CONCLUSION OF CHAPTER

Management and mining technology are two important factors that
influence the sustainable development of the stone mining for construction in
Vietnam. The content of the thesis research should be focused on these two tasks.
CHAPTER 3
RESEARCH ON TECHNOLOGICAL SOLUTIONS TO ENSURE
SUSTAINABLE DEVELOPMENT OF BUILDING STONE MINING IN
VIETNAM
3.1. Classification of stone mines used for construction materials according
to terrain conditions and the size of the mine
According to topographic conditions, open pit mines can be divided into
following categories:
Mines are located above the level of gravity drainage,
Mines are located below the level of gravity drainage,
Mines are located above and below the level of gravity drainage.
To make it easy for the classification and selection of mining technology,
mines located higher than the level of gravity drainage can be divided into
groups:
a. Single rocky mountain with foothills having circular circumference on
the scheme or having the same dimensions; plain surrounding terrain; relatively
small foothills’ perimeters.
8


b. Rocky mountain composed of a cluster of many different ridges of
different elevations; foothill clusters having circular circumference on the
scheme or having the same dimensions; plain surrounding terrain; relatively
large foothills’ perimeters.
c. Rocky mountain in form of long range; foothill’s length several times
as long as the width; many different ridges with different elevations; plain
surrounding terrain.

d. Rocky mountain in form of long range leaning against another rocky
mountains; only one exposed size, or two exposed sides with one surface being
smaller.
e. Rocky mountain or peaks of 50-70m high; moderately steep slopes; 37m-thick soil cover.
3.2. Research on classification of mining system for construction materials
in Vietnam and applying conditions
3.2.1. General overview of mining system and the classification of mining
system
There are many different perspectives of SE classification, but all of them
have the following common characteristics:
Based on the direction of movement and the growth of work route,
The main working object for classification is stripping stone,
SE is classified in general, irrespective of any specific mineral,
Terrain conditions are not taken into account.
With respect to construction stone, a more appropriate ES needs to be
studied.
3.2.2. Classification of SE in stone mining for construction materials
3.2.2.1. Available classification
There are many researches, classifications of Vietnamese and foreign
scientists such as Professor N.A.Maluseva, Dr. Nguyen Thanh Tuan, Prof., Dr.
Tran Manh Xuan, and Ass. Prof. Dr. Ho Si Giao, Ass. Prof. Dr. Bui Xuan Nam
et al.
3.2.2.2. Analysis of application conditions and completing the available SE
classification
Based on analysis of application conditions of the available SE
classification and new development characteristics of the mining sector, the SE
classification of building stone mine is classified as following criteria:
- The location of the mine compared to the level of gravity drainage;
- Cutting method on the horizontal surface;
- Conveyed method, shipping direction, the ability of combination

transported by gravity and mechanism, working platform.
- The selected mining ability;
- Waste dump location and drainage methods.
3.2.3. Proposal of SE classification of building stone mine (table 3.3)
9


Symbol

D

E

Group of mines
located both above
and below level of
gravity drainage (TD)

Combinati
on SE

Mixed
mining
system
Mining in
horizontal
or inclined
slicing

C

E

10

Combination of A, B and D.

Partially satisfied

Fully satisfied

Mining in inclined slicing and
transporting by truck or combination

D-2

Yes

Unsatisfactory

Yes

No

No

Yes
Yes
Yes
Yes

No
No
No

Working
platform

Partially satisfied
Partially satisfied
Unsatisfactory
Unsatisfactory

Fully satisfied
Unsatisfactory
Partially satisfied

Selected mining
ability

Mining in horizontal slicing and Fully satisfied
transporting by truck or combination

Mining in horizontal slicing, transport
by truck
a. Automobile
b. Conveyor
c. Hanger cable
Mining
in

horizontal
slicing,
transporting
by
truck
(loading
machines or bulldozers) and by gravity
through
a. mountainside
b. Spout
c. Well + audit
Mining in vertical slicing and
transporting by bulldozers and gravity
Mining in vertical slicing and
transporting by bucket excavator and
pass through mountainside (pit slope)
by gravity
Combination of SE A1 and A2; A and
B

Sub-Name of SE

D-1

A1 and A2
A and B

Mining in B-1
vertical
slicing

B-2

A-2

Mining in A-1
horizontal
slicing

Name of
SE

B

A

Symb
ol

Group of mines
located below the
gravity drainage (D)

Group of mines
located above the
gravity drainage (T)

Mine group

Table 3.3. Classification of SE in stone mining for construction materials

Outside
and
inside

Outside
and
inside
Outside
and
inside

No

No
No
No
No

Outside
No
No

Waste
dump

Free flowing
and forced

Forced

Forced

Free flowing

Free flowing
Free flowing
Free flowing
Free flowing

Free flowing
Free flowing
Free flowing

Drainage


3.3. Research and selection of suitable mining technology for building stone
mines located above gravity drainage
3.3.1. Research and selection of opening up method
3.3.1.1. Access road for building stone mines in terrain group (a)
When mining in horizontal slicing of the building stone mines in terrain
group (a), the spiral access road to transport is preferred. The application of the
spiral access road method depends on the height of rocky mountain, the
foothills area Sd (m2), the first mining area St (m2), the overall mountain slope
angle γ (degrees).
Hx =

S d - St
 . Ctg

(3.1)

,m

The parameters of the access road affects to the volume of road as: road bed
width (m), trench height hh (m) and slope angle of the trench banks  (degrees):
hh =

b sin . sin 
,m
sin(  -  )

(3.7)

The correlation between trench height and road bed width, overall
mountain slope angle is shown in figure 3.2. From figure 3.2, it can be seen that
when the overall mountain slope angle less than 400, height of trench increases
gradually, while overall mountain slope angle more than 40 0, the trench height
increases rapidly, which indicates the ability of making the spiral access road on
steep slopes is restricted.


28,6

Figure 3.2. Dependence of trench height on road
bed width and overall mountain slope angle

ChiÒu cao cña hµo (m)

³²


³²

20
³²

b = 7,5m

16,4


³²


³²

b = 5m


³²


³²







³²
³²b×nh ³²
Gãc trung
cña s-ên³²
nói (®é)³²

3.3.1.2. Access road for building stone mines in terrain group (b)
When mining in horizontal slicing of the building stone mines in terrain
group (b), the mixed access road to transport is usually applied, including general
trench, which could be simple common trench in the quarry combined with partcut subgrade and part-fill subgrade outside the mine. From the end of the simple
common trench or on favorable sites, the branched trenches circling through
mountain’s waist to reach the mountain apron, eventually spiral access road for
each mountain are dogged (Figure 3.3).
11


00
10
20
30

Figure 3.3. Chart showing access road can be applied

40
50
60
70

10

D
100
90

3

when exploiting the mountain peaks B, A, C, D and E
B

5

40

70
60
50

30
20
10
00

E
1
2

A
50

40

30

3.3.1.3. Access road for building stone mines in terrain group (c)
When applying SE in horizontal slicing and transporting by truck, two
approaches are applied: simple access road along one side of the mountain side,
or spiral access road at two mountain ends.
When applying SE in vertical slicing and transporting by bucket
excavator or bulldozer, the access road is built primarily for excavator,
bulldozer or truck; the access road is designed on one mountain side, while
other side is designed for stone transportation. The lower slope mountainside is
for access road, while the steeper slope mountainside is used for transport stone
from the top.
3.3.1.4. Access road for building stone mines in terrain group (d)
If the length of mountainside is long enough and slope angles are not
great, the simply access road or spiral access road are allowed, then the SE in
horizontal slicing and transporting by truck can be applied. If this SE method
is not applicable, then the SE in vertical slicing, shoveling and transporting by
bucket excavator, using bulldozer for vertical slices; or mining in horizontal
slicing for the upper and mining in vertical slicing for the lower are applied.
3.3.2. Determine the area of initial cut plan (leveling plan)
The area of initial cut plan must meet the following conditions:
- Ensure the normal operation for loading, transport equipments while
clearing stones in the top leveling process.
- Ensure the access road can reach to the altitude of the open up location.
3.3.2.1. Determine the area of initial cut plan when opening up by spiral access
road and transporting by truck (mine in terrain group a)
Considering the most difficult case that the access road is dug from this
contour to next contour (with the height h), where the initial cut plan is located,
must go through a spiral.

rt is notation of the converted radius of the area of initial cut plan:
12

00

40

30

20

50

80

70

4

C

(1), (2), (3), (4) and (5). Section of first initial cut

60

80

for building stone mines in terrain group (b)

rt =

h Kd
(
 ctg )m
2  .i

(3.10)

Subsequently, the area of initial cut plan is calculated according to
condition of opening up and transporting by truck:
St = rt2 , m2
(3.11)
When using bucket excavator for clearing rock and leveling tops on the initial
cut plan, the minimum area is (calculated via converted radius rt ').
r 't 

3R q 2mo  0,5bo  Lo
2

,m

(3.12)

Surface area calculated by rt’ is:
St’ = r’t2, m2

(3.14)

Where: Kd – access road stretching coefficient; - The overall

mountainside slope, degree; i - slope of access road, degree; Rq - The minimum
radius of curves in haul road, m; mo- safe distance from the edge of
mountainside to the trail of vehicle, m; bo – Width of truck, m; Lo – Length of
truck, m.
The selection of the initial cut plan using converted radius rt and rt ', the
greater value will be selected.
3.3.2.2. Determine the area of initial cut plan when opening up by spiral access
road at two mine ends or simple access road for mining in terrain group (c)
* Mining in horizontal slicing and transporting by truck.
In normal conditions, the length of initial cut plan can be approximated by
equation 3.15:
Lt =

h
 Rq , m
i

(3.15)

Where: h – height of working bench, m;
Width of the initial cut plan
Bt = k 2 (Rq + mo), m

(3.16)

Where: k - Additional coefficient.
* Mining in vertical slicing and transporting by excavator.
The minimum width of the initial cut plan must be equal to the width of
mining strip, and the length is equal to minimum length of the shoveling
stream.

13


* Mining in vertical slicing and transporting by bulldozers.
Minimum length of the first initial cut plan can be identified by equation
3.15, and the width is equal to the width of normal mining strip.
3.3.3. Research on applicable SEs
3.3.3.1. Research on applicable SEs for mines in terrain group (a)
1. Applying SE in horizontal slicing and transporting by truck
The spiral access road is the most favorable. After completing the pike
leveling and creating the initial cut plan, the first working bench can be started.
The most convenient position for first slice is at intersection between access
road and initial cut plan (Figure 3.7).

20

mining

10

Figure 3.7. Diagram showing the initial cut plan in slice

2
4

1

1. Contour line

40

3

2. Axis of spiral access road

MÆt b»ng
b¹t ngän
+50 m

3. Initial cut plan

5

4. Excavator
5. Truck
10

3
20 0

2. Applying SE in horizontal slicing, shoveling by loading machine, then
transporting along access road to truck at mountain apron.
When there is only one loading machine on mine, the mine’s yield will be
equal to productivity of loading machines, determined by the equation:
Qđ 

60 EK x .K ot
H .K
60
t xđ  2(rct  ct d ).

i
1000 vtbc

, m3/h

3.21)

Truck load q0 also be calculated according to the equation:
q0 

120 L
 Td  Tm
vtbo

H K  Kq
0,12
( N 0  1) t xd 
(rct  ct . d ) 
vtbc
i

 Ek x d

, ton

(3.28)

Where: E – bucket capacity of loading machine, m3; Hct - mountain height
calculated at the time of exploitation, m; rct - converted radius of corresponding
14

mining area Hct; Kd – access road stretching coefficient; vtbc - average speed of
loading machine, km/h; Kot - operational efficiency coefficient; Kx – shoveling
coefficient.
The loading machine’s productivity depends on the height of the mining
location and the change is illustrated in Figure 3.9.

³²



Figure 3.9. The change of the loading machine’s

³²



productivity (WA 600-3, E = 6,1m3) depends on the height
shoveling - transporting - unloading
1. Slope of access road i = 12%
2. Slope of access road i = 15%
3. Slope of access road i = 18%

N¨ng suÊt cña m¸y chÊt t¶i (m 3/h)

of mining location when loading machine worked as

³²


³²


³²

3

³²

³²


1

³²



2

³²


³²


³²



³²




³²cao khai
³² th¸c³²
ChiÒu
(m)


³²

3. Applying SE in horizontal slicing and transporting by loading machine
or bulldozers through the trough
When using this SE, the exploitation height can be upgraded, the volume
of pike leveling and access road can be decreased; this method is applied for
rocky mountain with restricted area of mountain apron. The downside is that
only one trough can be installed so that its yield is limited.
If considering the working time of loading machine, who loads stone into
trough and time of bucket excavator, who clears the stone pile at the foot of
trough are the same and equal to t, the productivity and capacity of loading
machine and bucket excavator can be calculated by using the equation bellow:
Qct =

Vd 60.Ec .K x .kot

t
Tck

,

m3/h

Where:
Ec =

Vd .Tck
60t.K x .kot

m3

(3.41)

And:
15


Qg =

Vd 60.Eg .K x .Kot

t
Tcg

, m3/h

Where:
Eg =

Vd .Tcg
60t.K x .kot

, m3

(3.42)

Where: Kx – Shoveling coefficient; Kot - operational efficiency coefficient; Tck
– Working cycle time of the loading machine, minutes; Tcg - Working cycle
time of the cable bucket excavator, minutes.
3.3.3.2. Research on applicable SEs for mines in terrain group (b)
The SEs can be applied:
1. When the mountain peaks are separated by a relatively large distance,
and the spiral access road can reach to the initial cut plan at the height of pike
leveling, the SE in horizontal slicing and transporting by truck can be applied.
2. In case truck cannot travel to the initial cut plan at the height of pike
leveling, the SE in horizontal slicing, shoveling and shipping directly by loading
machine, then unloading into truck at the mountain apron will be applied.
3. Applying SE in horizontal slicing and transporting soil and stone by
trough by loading machine.
4. In terms of steep slopes at the lower mountain part which is not suitable
for access road, then the conveyer trough to pour stone top down will be applied.
3.3.3.3. Research on applicable SEs of mechanized mining for mines in terrain
group (c) and (d)
When the slope of the mountainside is unsuitable for access road, the SE
in horizontal slicing and transporting by shoveling and bulldozer the stone over
pit slope to mountainside. Practically, the mixed SEs is applied.
Mining rock volumes in block for 1 meter length along the mountainside
with the mining strip width A (m) and bank height h (m) calculated by equation
bellow:

V1 = A.h , m3

(3.58)

The volume of stone in solid mass falling and cumulating at mountain
apron with the suitable rock pile height HCP (m) for shoveling is calculated for 1
meter length by the equation bellow:
16


V2 =

b
H cp
2Kr

=

H cp2 (ctg 0 - ctg )

It is well known that:
Ah = 0,5 H cp2

2K 0

=

H cp2 sin( -  0 )
,
2 K r sin sin 0

m3

(3.59)

V1 = V2, hence:

sin( -  0 ) 1
.
sin .sin 0 K r

= 0,5 H cp2 .

1
Kr

Rock pile height HCP (m) at mountain apron should be Hcp = 1,2 Hxmax
(Hxmax - the maximum working height of excavators) and  =

sin(  -  0)
sin .sin  0

,

we have:
0,72..H 2x max
Ah =
, m2
Kr

(3.61)

0,72..H 2x max
A=
,m
K r .h

The increase in Ah has important meaning as it increases the bank height
as well as promoting the working parameters of excavator; thereby mining
efficiency is increased in general.
The mining strip width A = Amin to ensure the movement of excavator for
starting the new mining strip (A  Amin), for the maximum bank height is
suggested; then the bank height will be calculated by equation bellow:
0,72..H 2x max
hmax =
,m
A min .K r

(3.65)

Time of moving of the excavator to fully exploit the rocky mountain:
Tdk =

Ltbn H tb B tb
.
.
1000 .v h
A

,hour

Where: Btb - The average width of the rocky mountain, m.
Ltbn - The average length of rocky mountain, (m)
Htb - The average height of the rocky mountain, m.
For a particular mine, Ltbn, Htb, Btb are determined, the velocity v depends
on the type of excavator is known, therefore moving time of no load excavator
is inversely proportional to Ah. Ah increase will reduce T dk. Table 3.8 shows
bank height and width of mining strip that might be applied for for some type of
excavators.

17


Table 3.8. Suggestion for selection of bank height h and width of mining
strip A for different excavators
Types of excavator
working at foot of
Seq
the line and on the
bench
1

2
3

Front shovel CAT5680 (made in
America)
Front shovel ЭҐ-6
(Made in Russia)
Bucket excavator –

construction type
Э2505-XD-2 (Made
in Russia)

Capacity Shoveling Bank
of bucket height
height
m3
Hxmax, m h, m

Width
of
mining
strip A,
m

Applied
borehole
diameter,
mm

5,2

11,12

10,0

6,88

105

6,0

13,0

12,0

7,8

127

2,5-3,2

10,0

8,0

7,0

105

3.3.4. Study on application of selection criteria for appropriate mining technology
In the case of options for comparison are relatively simple and short time
mining, the following criteria are applied.
Ci = Cki + Ed.Ki, đ/m3 min
(3.71)
Where: Ci – Costs calculated for exploiting1m3 monolithic rocks under option
no. i, đ/m3; Cki - Costs for exploiting1m3 monolithic rocks under option no. i, đ/m3; Ed
- The coefficient of efficiency norms for investment; Ki - Basic investment rate, đ/m3.
In the case of options for comparison are relatively complex and long time

mining, the Net Present Value (NPV) criteria will be applied:
n

NPV =  (G t - C t )a t  max và NPV  0

(3.72)

t 0

Where: at - Discount factor in year t, Gt - Cash flow received in year t, Ct Cash flow spent in year t.
CONSLUSION OF CHAPTER
1. The mine classification according to type of terrain conditions and mine’s
size is studied and determined in order to set up the basis for the selection of SE
and mining equipment synchronization.
2. The theoretical and practical issues on design and specific calculation
methods for parameters of open up, parameters of SE, order of bench
preparation for group mines in mountain area are completed and upgraded.
18


CHAPTER 4
STUDY ON MANAGEMENT SOLUTIONS TO ENSURE
SUSTAINABLE DEVELOPMENT OF BUILDING STONE MINING
SECTOR IN VIETNAM
4.1. The specific recommendations of modalities for mining licensing
Scale of reserves for auctioned mining rights cannot take arbitrary but
must be within a certain limit to ensure business profits; especially for mines
located below the gravity drainage.
Vxdh (G - C) = max và Vxdh (G - C) > 0
(4.1)

Where: Vxdh - Reasonable scale of stone reserves that business must pay
for mining rights;
G - The value of a unit of building stone is mined (monolithic), đ/m3; C - Total
costs for the exploitation and processing of 1m3 building stone, đ/m3.
Value of Vxdh is determined from volume of certain building stone Vxd
located inside the outskirt of mine.
Value Vxd is calculated by using preselected size of pit floor; ensure mine
and transport equipments to operate normally at a minimum level; depends
largely on mining depth (Figure 4.1).
4.1.1. Determination of the volume of building stone Vxd
Bm
ß

ß
Bt

ho

Ho




Bd
Lm
A
ß

ß

Lt

ho

Ho

d

d
A
Ld

Figure 4.1. Chart of determining the volume of building stone Vxd
19


Final equation for determining the volume of building stone Vxd:
 2S  H ( B  '  L  )   'H 2 
d
0
d
d
0
Vxd= 

Sd2  (Bd '  L d ) H 0 Sd   ' Sd H 02  H 0

3

(4.9)

Where: Bd – width of pit floor, m; Ld length of pit floor, m; Sd - area of pit
floor, m2; H0 - the mining depth of the mine, m; 1 – pit slope towards the bank,
degrees; 2 – pit slope towards the pillar, degrees; d – pit slope of two mine end
banks, degrees;  = ctg1 + ctg2; ' = 2ctgd.
4.1.2. Determining the volume of cover on building stone
The equation for calculating volume of cover on building stone is:
Vp =  St

 h 0ctg  ( Lt  Bt )  2h 02ctg 2  

h0, m3

(4.15)

Where: Bt –upper width of mine is calculated for building stone, m; L t upper length of mine is calculated for building stone, m; St –upper surface area
of mine, m2;  - Stable angle of the cover, degrees; h0 - thickness of cover, m.
4.1.3. Determining the cost of mining and processing of building stone
General equation:
Cxd = Ckn+Cxb+Cvt+Cns+Ctn+Cd+Cmt+Cg+Ctp+Cq+Ck, đ/m3

(4.16)

Where: Costs for exploitation and processing of 1m3 building stone (Cxd)
including: cost of drilling and blasting (Ckn), shoveling and loading (Cxb),
transporting (Cvt), crushing and screening (Cns), cost of surface and groundwater
drainage (Ctn), compensation or leasing land for mining (Cd), environmental
protection fee (Cmt), fee for granting mining rights (Cg), royalty and other fees
(Ctp), management costs (Cq) and other expenses (Ck):
On the other hand, this cost is also determined by the equation:

Cxd = A + B

Dong/m3

(4.30)

Where:
A - Part of the cost does not depend on the depth of exploitation, đ/m3;
B - Part of the cost depends on the depth of exploitation, đ/m3;
B = 0,5[Bd + Ld + 2hoctg +

h0 . Kd
K
Sc

] + 0,5[ d + 0,5 (ctg1 + ctg2 + 2 ctgd] + L
1000
i
i

( H o  ho ) SmF  36590
S m  0,35 Pm ( H o h o )  0,5( H o h o ) 2 ].S dm
đ/m3
(
)C bn  [
2
Ad
V xd

Where: Sm – mine’s surface area, m2; i - slope of access road, đv.

20

(4.29)


4.1.4. The determination order of the reasonable scale of building stone reserves
The method of valuation of Vxdh is as same as determination of the reasonable
depth of the mine exploitation when size of pit floor is known. When the
appropriate depth is determined, the volume of building stones in that depth range
will be determined.
Profits earned from the quarrying include two parts: The part of building
stone mining L1 and part of exploitation and use of cover layer L2.
Total profit:
L = L1 + L2> 0 and
Where: L1 = Vxd(G - C)
L2 = Vp(Gp - Cp)
Where Gp and Cp - the entire value and cost of removing 1m3 cover layer.
When using informatics to solve the problem, the block diagram is as
following (Figure 4.2).

Figure 4.2. Block diagram defining reasonable scale of building stone
reserves for auction of mining rights
21


Based on above outlined block diagram, software for reasonable
calculation of stone reserves for auction of mining right is written.
The software is written in C# language in the most minimalist form. After
the input parameters are entered, the software will calculate and the output table
(4.1), (4.2) and (4.3) will be given, which can be managed, stored, meeting the

requirements for easiest reference.
INTRODUCTION OF SOFTWARE FOR REASONABLE
DETERMINATION OF MINING RESERVE
Running the program
 Select "Calculate" on Menu bar

 Enter data into the program

 Select the output as individual table of results. In this process, the
destination folder to save the results should be chosen.
22


4.2. The specific recommendations on state management
4.2.1. Management on planning
Management of mining activities based on approved plan.
Compiling the adjacent separated small mines into a large mine.
4.2.2. Comprehensive inspection based on "Self-test sheet"
The first stage: From the time of granting mining license to the time that
project finish development opening and the mine into operation.
The second stage: Normal production phase of the mine.
The third stage: The mine closing.
Comprehensive inspection based on "self-test sheet".
4.2.3. Research formulating mechanisms to coordinate inspection building
stone quarrying operations across sectors and between the central and localities
Promulgate regulations on coordination, exchange of information and
periodic reports;
Strengthen the organization of state management agencies on minerals.
CONCLUSION OF CHAPTER
1. The licensing should be considered to ensure the normal operation of

the mine.
2. Incentive policies should be made to cooperate for exploitation on a
large area, facilitate the application of advanced mining techniques.
3. Continue to nurture, capacity building and enhancement for staff who
work in the field of state management on minerals.
4. There should be consistency between the central agencies and between
the central and local authorities in the inspection, testing on the basis of the
content of "Self-test sheet"
5. Use the reserve calculation software to determine the scale of mines.
CONCLUSION
1. In this thesis, mining technology for building stone in the different conditions
in Vietnam and other countries has been reviewed and assessed, and based on
that, technology solutions suitable for the specific conditions in Vietnam have
been discussed, completed and selected.
2. Mine types have been classified according to terrain conditions and sizes for
the selection of mining technology and device synchronization. Exploitation
23