Subharaj Chakraborty completed a summer internship project assessing mining operations at Ambuja Cements Ltd.'s Kashlog limestone mine. Key findings included the crusher operating below capacity and inconsistent dumper cycle times due to idling. Suggestions focused on minimizing idle time through optimizing dumper-excavator ratios and enforcing safety procedures like proper personal protective equipment usage and speed limits. The internship provided insights into improving mining efficiency and safety practices.
2. COMPANY INTRODUCTION
Ambuja Cements was set up in 1986. In the last decade the company has
grown tenfold. The total cement capacity of the company is 18.5 million
tonnes. Its plants are some of the most efficient in the world. With environment
protection measures that are on par with the finest in the developed world.The
Group's principal activ ity is to manufacture and market cement and clinker for
both domestic and export markets.
COMPANY BUSINESS
The company's most distinctiv e attribute, however, is its approach to the
business. Ambuja follows a unique homegrown philosophy of giv ing people
the authority to set their own targets, and the freedom to achieve their
goals. This simple vision has created an environment where there are no
limits to excellence, no limits to efficiency. And has proved to be a
powerful engine of growth for the company.
3. KASHLOG MINES
➢The Kashlog limestone mine of Ambuja Cement is located near village
Kashlog in Arki Tehsil of Solan District in Himachal Pradesh, its mining
lease area is about 488 hectares.
➢This mine was awarded SitaRam Rungta Memorial award for social awareness
for the year 1998-1999 by Federation of Indian Mineral Industries (FIMI).
➢The total requirement of both the cement Plants Suli and Rauri is met from this
mine.
➢Crushed limestone from mine to plant is transported by a 3.2 Km long closed
overland belt conveyor system in an Eco-friendly manner.
➢The exploitation of limestone is being carried out by highly mechanized open-
cast mining system.
➢The 10m height benches are planned to have a slope of 70° with an ultimate pit
slope of 45°.
➢Drilling is carried out by deploying hydraulic drills for primary blasting
purpose. Around 90% of the production requirement is met by drilling and
blasting.
4. Crushed limestone from mine to plant is transported by a 3.2 Km
long closed overland belt conveyor system in an Eco-friendly
manner.
5. OBJECTIVES
• To understand the operational activities of the mining process.
• To calculate the cycle time of the various equipments of the
mining process like dumpers, crushers etc.
• To study about the safety precautions in the mining process.
• To give a report about the assessment of the mining process to
the management.
• To report about the violations of the safety precautions and
misconduct done which may or may not result to production
loss.
• To give a presentation at end of the project to the management
and submit a good project hard-copy to the company.
6. RESEARCH APPROACH
There are different research methodology has been taken place to
complete the project:
First studying about mining activities from the internet.
Second referring the books related to operations & supply
management, to implement the various techniques and models for
the project design and management.
Third consulting with the various employees of different designations
to extract the data for the project and understanding the environment
of work.
Fourth to go to the field of extraction of limestone and manually
gather the recent cycle-time of various equipments.
Fifth going to the different sections to gather the data at different
points.
Sixth I have also done some calculations at certain points.
7. FINDINGS/ PROBLEMS
➢It has been observed that crusher is of under capacity. Crusher should be of 1200 TPH to
feed both the plants from single mine. Average crusher TPH in a shift was found to be 944
TPH on an average.
➢It has been observed that the hopper on a particular shift was only 79% full at maximum
time interval instead of 100% or 90% which means the interval of dumpers to dump the raw
lime-stones into the hopper is not adequate.
Some of the time intervals between the dumpers are as follows:
From first dumper to 2nd : 5 min
From 2nd to 3rd : 2 min
From 3rd to 4th : 2:30 min
From 4th to 5th : 3:45 min
From 5th to 6th : 8:26 min
From 6th to 7th : 4 min
From 7th to 8th : 9:30 min
From 8th to 9th : 1 min
From 9th to 10th : 13 min
Taking the average time between the dumpers, the time interval between in approx 5:30 min
which is not enough to fill the hopper and utilize its optimum capacity.
9. FINDINGS/ PROBLEMS
Here some sample of the dumpers cycle time is taken in a particular shift and
depended upon this some findings have been calculated:
SL Transport Spotting Loading Transport Spotting Unloading Total
no. time to time in time time to time to time to Cycle
site site crusher crusher crusher time
1 6:20 min 3 min 1:35 min 8 min 4:30 min 00:21 sec 23:06
min
2 5 min 3:54 min 2:00 min 4:12 min 26:91 00:23 sec 15:16
sec min
3 3:51 min 2:58 min 2:15 min 4:00 min 1: 46 min 0:30 sec 14
min
4 3:37 min 15 min 2:56 min 4:00 min 00:16 00:34 sec 25:43
sec min
By looking at the table we can see that the cycle time variation is large due to
variation in lead distance. The highest cycle time here is nearly 26 min. After
seeing the figures it could be easily pointed out that the variation is likely due
to the idling time at crusher and loading point of excavator.
10. FINDINGS/ PROBLEMS
➢The problem of excessive idling time in the extraction area is more likely due to
the excess of dumpers in compare with the PC Excavators. Due to this after
completing the cycle up to unloading and return for re-load, more than 2
dumpers have to wait in a line before the previous dumpers is loaded and
ready to go. This is mainly due to low crusher capacity.
➢Some times in place of 3 dumpers which are needed for the purpose, 4 dumpers
are used and so due to the spotting time excessive amount of fuel is
consumed. As we know that a dumper nearly consumes 25-28 liters per hour
and in idle time In engine start position it consumes 5% of the total fuel per
hour. So, nearly 1.4 liters it is consuming unnecessarily per hour. And
considering it in a financial year it is a big loss.
➢Sometimes it has been observed that the dumpers capacity is 50 tons but some dumpers
carry 38 tons, 40 tons, some times 55 tons-58 tons which is over weight, so sometimes
dumpers adequate capacity utilization lacks for which some production problem may
also arise.
11. In place of
one dumper 2
dumpers are waiting
for loading.
This is a picture has been taken at the lime stone extraction
area.
12. SUGGESSIONS
●The cycle time of the equipments should be minimized like the dumper by
employing certain techniques like minimizing the idle time of the
dumpers at the extraction area by limiting the use of more dumpers in
place of few needed.
●Or by increasing the numbers of PC excavators in the ratio of the dumpers
like now there are 3 excavators, there should be 1 more.
●When the dumpers are in idle position the engine should be switch off
which may result in saving the fuel.
●The maximum attention should be given to utilize the optimum capacity of
the hopper at the crusher, so that production can be increased.
●Optimum utilisation of the machines should be done to increase the output.
13. SAFETY PRECUATIONS UNDERTAKEN IN MINING
AREA
Only the authorized employees are permitted to handle the explosives.
There are demarcations around the blast location like barricades, flag
signs etc.
The blast holes are being loaded under the control and supervision of the
designated competent person.
The controlled blasting technique is being adopted.
Cellular phones are not allowed in the blasting zone.
The explosive van's speed should not exceed 25km/hr.
Warning signals are given within a radius of 500 meters from the place of
firing.
After the blasting a siren is blown as signal if it is all clear and safe.
As the blasting is very dangerous for the eye at some distance also, safety
glasses should be provided and used at the blasting site.
14. SAFETY PRECUATIONS
➢In the mines the Helmet & safety boots should be worn every time
specially in the field.
➢The use of safety glasses should be encouraged
➢In the night shift there should be adequate light facility.
➢The vehicles speed at the mines area should not exceed 30 km/hr under
any conditions.
➢The distance between the dumpers should be more then 10 meters..