Interview Preparation CMR/MMR First Class/Second Class Part-2

21. What are the provisions of drinking water in Mines rule?

Refer Mines rule. This question was frequently asked by candidates in last year interview.

 

22. What is National Disaster response force?

The National Disaster Response Force (NDRF) is a specialised force constituted for the purpose of specialist response to a threatening disaster situation or disaster under the Disaster Management Act, 2005.

The Apex Body for Disaster Management in India is the National Disaster Management Authority (NDMA). The Chairman of the NDMA is the Prime Minister.

The immediate responsibility for Disaster Management in India’s political system is that of the State Government.

The ‘nodal Ministry’ in the central government for management of natural disasters is the Ministry of Home Affairs (MHA). This question becomes important because in Lalmatiya Coal Mines accident NDRF was involved in rescue operation.

 

23. Why rescue brigade, rescue personnel and rescue arrangement maintained at mines and company level often do not prove to be suffice in case of Mining disasters?

Recent mishap of Lalmatiya Coal Mines again highlighted the inadequacy of rescue arrangement made at mines and company level. Inefficiency of rescue arrangement is due to several reasons which includes:

• Lack of infrastructure in terms of modern techniques, modern equipment etc.
• Lack of training of rescue personnel
• Non availability of specialized rescue team at company level
• Lack of a proper policy to ensure quick and timely response

 

24. What is Maslow’s hierarchy of needs?

Maslow’s Hierarchy of Needs (often represented as a pyramid with five levels of needs) is a motivational theory in psychology that argues that while people aim to meet basic needs, they seek to meet successively higher needs in the form of a pyramid.

The levels are as follows:

·              Self-actualization – includes morality, creativity, problem solving, etc.

·              Esteem – includes confidence, self-esteem, achievement, respect, etc.

·              Belongingness – includes love, friendship, intimacy, family, etc.

·              Safety – includes security of environment, employment, resources, health, property, etc.

·              Physiological – includes air, food, water, sex, sleep, other factors towards homeostasis, etc.

 

25. What is difference between coking coal and thermal coal?

The classification itself is utility based. The coal used for making coke is coking coal; whereas coal burnt for producing heat in thermal power plants is referred to as thermal coal. The former is used for metallurgical purposes and the latter for Power generation.

However, the fundamental difference between two types of coal is in their caking property. Non-coking coal (usually referred to as thermal coal) cannot form cake when heated in absence of air; whereas, when coking coal is heated in absence of air (carbonisation) the constituents start fusing and form a large chunky mass, known as coke. The coking coal is also referred to as Metallurgical Coal, because it's mainly used in metal extraction (i.e. Iron Making).

Gross Calorific value is usually determined for Non-coking coal (as its utility is calorie based); and, that's why the classification of non-coking coal is GCV Based. Whereas, utility of coking coal lies in its reducing property, which depends on fixed carbon content (or the amount of impurities); thus, the classification is based on ash content (lesser the better).

Typical value of GCV is around 6500 kcal/kg for ST-II Coal. You can determine it in the laboratory using Bomb Calorimeter. However, if you are looking for empirical formulae, it depends on what type of analysis you have done.

If you have proximate analysis data, you can use GCV= 85.6 (100 – ( M % + 1.1 x Ash %)) – 60 x M % ; for M (moisture) > 2.0 %; in case of ultimate analysis data, you can use Dulong's equation.

 

26. What is the difference between coking coal and caking coal?

When many bituminous coals are heated, they soften and form a plastic mass that swells and resolidifies into a porous solid. Coals that exhibit such behaviour are called caking coals.

Strongly caking coals which yield a solid product (coke) with properties suitable for use in a blast furnace, are called coking coals. All coking coals are caking but not all caking coals are suitable for coke making.

 

27. What are the differences between coking coal and non-coking coal?

Coals as straight or in blend which on carbonization produce hard coke are known as coking coals.

 

28. What are important Properties of Coal?

The most important properties of coal to the combustion engineer are as follows:

· Proximate analysis – to determine the moisture, ash, volatiles matter and fixed carbon

· Ultimate or elementary analysis – to determine the elemental composition of the coal

· Calorific value

· Caking properties – for bituminous coals only

· Grindability – where the coal is to be pulverised

 

29. Define Proximate and Ultimate analysis?

These tests are undertaken following standard procedures laid out in British Standard 1016 pt 3, 1973.

Proximate analysis is the simpler of the tests and is used to determine the moisture, ash, volatile and fixed carbon content. Ultimate analysis is used to determine the elemental composition in terms of Carbon, Hydrogen, Sulphur, Nitrogen and Oxygen by difference.

The percentages can be reported by weight in a variety of different ways:

As sampled (as received) – exactly as the sample came to the lab

Dry – based on the air dried sample (not completely dried)

Dry, Ash free – based on the air dried sample with ash removed

Dry, Mineral Matter Free (DMMF) – based on the air dried sample with all mineral (inorganic) matter removed

Mineral matter is not directly measured but may be obtained by one of a number of empirical formulae based on the ultimate and proximate analysis. Further empirical relationships are also possible between carbon, hydrogen, oxygen and CV. The most commonly used is Seyler's chart.

 

30. Process of manufacturing of coke?

Coke is manufactured from the carbonisation of prime coking coals. Carboniastion is performed for three main reasons: To make a smokeless fuel for domestic/industrial applications: to provide a coke for some other process (most importantly blast furnaces); to produce a combustible gas. However other important products are formed including coal tar which in the past was a very important chemical feedstock.

Raising the temperature of coking coals in the abscence of oxygen results in their devolatilisation and the formation of a solid fuel, coke, which has a porous structure. Two types of coke can be made, hard and soft. The difference is in the temperature of carbonisation. Soft coke is carbonised at lower temperatures 600-700C. This results in a product with a reduced volatile content of the order 9% and hence better combustion characteristics.

Hard coke is carbonised at higher temperatures and resulting in devolatilisation and loss of porosity. Combustion characteristics are reduced making these cokes only suitable for more specialist purposes such as manufacture of carbon electrodes or in blast furnaces.

 

31. What is the difference between coal and charcoal?

Coal is the mineral anthracite, a fossil fuel composed of carbon and created over millions of years by the pressurizing and long term breakdown of organic materials like plant remains. It is a black mineral found below the ground and mined out like any other rock or mineral. It is considered sedimentary but can become metamorphic w/ continued exposure to heat & pressure. It is used for burning to supply heat and to make coal gas and coal tar. Charcoal is produced by slow heating of wood or other combustible substances in the absence of oxygen. It is also a black substance made by burning wood slowly in an oven with a little air, and can be used as a filtering material or as fuel or for drawing.

It is similar in some respects to coal, but is less dense and more porous. So the main difference between the two is that coal is a mineral and charcoal is the ultimate form of burnt wood.

 

32. What is the difference between bituminous coal and anthracite coal?

The main difference is the amount of carbon. Anthracite is harder and contains more carbon. Bituminous coal is a sedimentary rock and anthracite coal is actually a metamorphic rock that has undergone tremendous pressures, usually from mountain building events.

 

33. What is the different between graphite and coal?

Graphite is the highest grade of coal. It requires a much higher temperature to burn though so it isn't used as a fuel.

 

34. What is training?

The organized procedure by which people learn knowledge and/or skill for a definite purpose. Training refers to the teaching and learning activities carried on for the primary purpose of helping members of an organization acquire and apply the knowledge, skills, abilities, and attitudes needed by a particular job and organization.

 

35. Why training is necessary?

Every organization should provide training to all the employees irrespective of their qualifications and skills.

Specifically the need for training arises because of following reasons:

1. Environmental changes:

Mechanization, computerization, and automation have resulted in many changes that require trained staff possessing enough skills. The organization should train the employees to enrich them with the latest technology and knowledge.

2. Organizational complexity:

With modern inventions, technological upgradation, and diver­sification most of the organizations have become very complex. This has aggravated the problems of coordination. So, in order to cope up with the complexities, training has become mandatory.

3. Human relations:

Every management has to maintain very good human relations, and this has made training as one of the basic conditions to deal with human problems.

4. To match employee specifications with the job requirements and organizational needs:

An employee’s specification may not exactly suit to the requirements of the job and the organization, irrespective of past experience and skills. There is always a gap between an employee’s present specifications and the organization’s requirements. For filling this gap training is required.

5. Change in the job assignment:

Training is also necessary when the existing employee is pro­moted to the higher level or transferred to another department. Training is also required to equip the old employees with new techniques and technologies.

 

36. What are different Types of Training?

Various types of training can be given to the employees such as induction training, refresher training, on the job training, vestibule training, and training for promotions.

Some of the commonly used training programs are listed below:

1. Induction training:

Also known as orientation training given for the new recruits in order to make them familiarize with the internal environment of an organization. It helps the employees to understand the procedures, code of conduct, policies existing in that organization.

2. Job instruction training:

This training provides an overview about the job and experienced trainers demonstrates the entire job. Addition training is offered to employees after evaluating their performance if necessary.

3. Vestibule training:

It is the training on actual work to be done by an employee but conducted away from the work place.

4. Refresher training:

This type of training is offered in order to incorporate the latest development in a particular field. This training is imparted to upgrade the skills of employees. This training can also be used for promoting an employee.

5. Apprenticeship training:

Apprentice is a worker who spends a prescribed period of time under a supervisor

 

37. What are the methods of training?

On-the-job-training methods: Job rotation, Coaching, Job instruction, committee assignments, internship training.

Off-the-job-training methods: case study method, role play, business games, lectures, simulation etc

Stay in tune for third part.