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Pumice Stone Mining Company & Pumice Exporter From Indonesia

Pumice Stone Mining Company & Pumice Exporter From Indonesia

Contact Us Via Phone / Whatsapp : +62-877-5801-6000

Our company is the producer of export quality pumice stone from Lombok Island of Indonesia. Our Company as the one of mainstay export product FOB and go International, we have :

  • East Lombok Island locations (50-100 hectares) ; in the river washing pumice stone and dried (200 workers).
  • West Lombok Island locations (30-50 hectares) ; the location beach front and mineral waters direct to washing pumice stone and dried (50 workers).

We are the biggest producer and exporter of pumice stone (origin Lombok island, Indonesia). We pack the pumice very good and we are ready to ship.

Packing and weight of pumice stone.

  • Our pumice stone is packed in PP. Woven bag size 60 x 100 cm.
  • The weight of pumice stone is about 23 kgs / bag with minimum weight 22 kilogram per-bag and maximum weight 28 kilogram per-bag.
  • Weight of pumice stone is depend on the dryness of the stone.
  • FOB Port : SURABAYA City Sea Port ( East Java Province of Indonesia )

Export Quality Pumice Stone

  • Brand names: Lombok Pumice, Deer Pumice, Tiger Pumice, Dragon Pumice, Indonesia Pumice, etc
  • Lead time for shipment payment to be advise for you shipping arrange container at Surabaya Closest port of dispatch port surabaya.
  • Present export markets: Taiwan, Korea, Hong Kong, Thailand, Bangladesh, India, Srilangka, Vietnam and target markets world wide.

Quality standard international / specifications / size

  • Color: Ash grey,
  • Condition: Dry, clean & processed,
  • Size: 1-2 cm, 2-3 cm, 2-4 cm and 3-5 cm
  • Packing : PP woven bag
  • Bag size: 60x100cm,
  • Bag weight: Approx. 25 kilogram per-bag (min 22 KG; max 28 KG).
  • Minimum order: 1 x 40’HC
  • 40′ feet high cube (HC) load: 1100 bags.
  • Quantity volume supply ability: around 200. 000 bags / month for dry season in March, April, May, June, July, August, September, Oct and middle November.

PUMICE STONE

CHEMICAL STUDY PROGRAM – FACULTY OF MATHEMATICS AND NATURAL SCIENCES – MATARAM UNIVERSITY – 2010

Author : AGUS SUPRIADI RIDWAN, LALU RADINAL FASHA, NI WAYAN SRIWIDANI, NUR WILDAWATY, NURAINI YUSUF

CHAPTER I INTRODUCTION

Geographical and geological position of Indonesia which is located in the tropics, where most of the area in Indonesia is located on a volcanic mountain line. Therefore, Indonesia is very rich in types of natural rocks, such as class C minerals which are widespread in several regions in Indonesia. Class C minerals include limestone/limestone, river stone, sand (backfill sand and iron sand), coal, roof tile, gravel, gypsum, calcite, manner, pyrite, silt, claystone, trass, andesite, pumice. , etc. But in this paper, we only discuss pumice.

Pumice or pumice is an industrial mineral that belongs to class C which plays a significant role in the industrial sector, both as a main ingredient and as an additional material. Pumice is a volcanic product that is rich in silica and has a porous structure, which occurs due to the release of steam and gases dissolved in it when it is formed, in the form of solid blocks, fragments to sand or mixed fine and coarse. Pumice consists of silica, alumina, soda, iron oxide. Color: white, bluish gray, dark gray, reddish, yellowish, orange. The chunks when dry can float on the water.

Many general investigations and exploration of pumice have been carried out in Indonesia, one of which is in several areas scattered on the island of Lombok, NTB. Lombok Island is one of the largest pumice-producing areas in Indonesia. Exploration is generally carried out by open pit mining and manually, which does not require special equipment to obtain it. Most of the pumice obtained from mining is only in the form of pumice which is separated based on its size which is then sold with variations in these sizes. However, in the subsequent processing to produce a useful product, it is carried out by companies that tend to use pumice as raw material, for example the paint industry.

Pumice can be applied in the industrial sector and the construction sector. Its application in the industrial sector tends to produce complementary goods,

such as paint, plaster, and cement. Meanwhile, the construction sector tends to produce building raw materials, such as lightweight aggregator concrete.

The development of the industrial and construction sectors, especially in developed countries, has shown a significant increase, and this has resulted in the increasing demand for Indonesian pumice stone. In terms of supply, pumice production in Indonesia mostly comes from West Nusa Tenggara and the rest from Ternate, Java and others. Meanwhile, imports of pumice can be said to be non-existent or domestic needs have been met.

In West Lombok, there are at least 20 pumice processing companies spread across various regions. However, currently pumice mining in West Lombok is reaping many problems, especially environmental problems, where most of the mining is carried out without a permit and does not pay attention to environmental sustainability.

Pumice waste from pumice sieving itself has damaged the environment. This is due to its disposal on land that is still productive. So an effort is needed to overcome this waste. One of them is by using pumice waste as a building material, in the form of bricks, paving blocks, concrete tiles, lightweight concrete. This is because apart from being one of the pumice waste management, it is also an economical alternative for building materials, as well as job opportunities for the community.

CHAPTER II.

2.1 Definition

Pumice (pumice) is a type of rock that is light in color, contains foam made of glass-walled bubbles, and is usually referred to as silicate volcanic glass rock.

These rocks are formed from acidic magma by the action of volcanic eruptions that release the material into the air, then undergo horizontal transportation and accumulate as pyroclastic rocks. Pumice has high vesicular properties, contains a large number of cells (cellular structure) due to the expansion of the natural gas foam contained in it, and is generally found as loose material or fragments in volcanic breccias. While the minerals contained in pumice are: Feldspard, Quartz, Obsidian, Kristobalite, Tridymite.

2.2 Forming process

Pumice occurs when acidic magma rises to the surface and comes into contact with large air suddenly. Natural glass foam with the gas contained in it has a chance to escape and the magma freezes suddenly. Pumice are generally found as fragments that are ejected during volcanic eruptions, the size is from gravel to boulder.

Pumice commonly occurs as melt or runoff, loose material, or fragments in volcanic breccias. Pumice can also be made by heating obsidian, so that the gas escapes. Heating performed on obsidian from Krakatoa, the temperature required to convert obsidian into pumice on average 880oC. The specific gravity of obsidian which was originally 2.36 dropped to 0.416 after the treatment because it floated in the water. This pumice stone has hydraulic properties. Pumice is white-grey, yellowish to red, vesicular texture with varying hole sizes, either related to each other or not scorched structure with orientated orifices.

Sometimes the hole is filled with zeolite or calcite. This rock is resistant to freezing dew (frost), not so hygroscopic (sucking water). Has low heat transfer properties. The compressive strength is between 30-20 kg/cm2. The main composition of amorphous silicate minerals.Other rock types that have the same physical structure and origin as pumice are pumicite, volcanic cinter, and scoria. While the minerals contained in pumice are feldspar, quartz, obsidian, cristobalite, and tridymite.

Based on the manner of formation (desposition), particle size distribution (fragment) and the material of origin, pumice deposits can be classified as follows:

  • Sub area
  • Subaqueous
  • New ardante; i.e. deposits formed by the horizontal outward movement of gases in lava, resulting in a mixture of fragments of various sizes in a matrix form.
  • Result of re-deposit (redeposit).

From the metamorphosis, only areas that are relatively volcanic will have an economical pumice deposit. The geological age of these deposits is between tertiary and present. Volcanoes that were active during this geological age included the Pacific Ocean fringe and the route from the Mediterranean Sea to the Himalayas and then to East India.

2.3 Properties of pumice

The chemical properties of pumice are as follows:

a. Its chemical composition:

SiO2 : 60.00 – 75.00%
Al2O3 : 12.00 – 15.00%
Fe2O3 : 0.90 – 4.00%
Na2O : 2.00 – 5.00%
K2O : 2.00 – 4.00%
MgO : 1.00 – 2.00%
CaO : 1.00 – 2.00%
Other elements: TiO2, SO3, and Cl.

b. Loss of glow (LOI or loss of ignition): 6%

c. pH : 5

d. light color

e. Contains foam made of glass-walled bubbles.

f. Physical properties:

Bulk weight : 480 – 960 kg/cm3

Water infiltration : 16.67%

Specific Gravity : 0.8 gr/cm3

Sound transmission: low

Compressive strength to load ratio : High

Heat conductivity: low

Resistance to fire: up to 6 hours.

CHAPTER III. MINING

3.1 Mining Engineering

Pumice as an excavated material is exposed near the surface, and is relatively not hard. Therefore, mining is carried out by open pit mining or surface mining with simple equipment. Separation of impurities is done manually. If a certain grain size is desired, grinding and sifting processes can be carried out.

1) Exploration

Searching for the presence of pumice deposits is carried out by studying the geological structure of rocks in the area around the volcanic pathway, among others by searching for outcrops by geoelectric or by drilling and constructing several test wells. Next, a topographic map of the area is made which is estimated to contain large-scale pumice deposits in order to carry out detailed exploration. Detailed exploration aims to determine the quality and quantity of reserves with more certainty. Exploration methods used include drilling (hand drill and machine drill) or by making test wells.

In determining which method to use, one must look at the condition of the location to be explored, which is based on the topographic map made at the prospecting stage. Exploration method by making test wells, begins with making a rectangular pattern (can also be in the form of a square) with a distance from one point or from one test well to the next test well between 25-50 m. The equipment used in making the test wells include hoes, crowbars, belincong, buckets and ropes.

Exploration by drilling can be done using a drill equipped with a bailer (sample catcher), either hand drill or machine drill. In this exploration, more measurements and mapping were also carried out

details for use in reserve calculations and mine planning.

2) Mining

In general, pumice deposits are located close to the earth’s surface, so mining is carried out by open and selective mining. Overburden stripping can be done with simple tools (manually) or with mechanical tools, such as bulldozers,

scrapers, and others. The pumice layer itself can be excavated using an excavator such as a backhoe or a power shovel, then loaded directly into trucks to be transported to the processing plant.

3) Processing

In order to produce pumice with quality that is in accordance with export requirements or needs in the construction and industrial sectors, pumice from the mine is processed first, among others by removing impurities and reducing its size.

Broadly speaking, the pumice processing process consists of:

a. Sorting (sorting); to separate clean pumice from pumice which is still a lot of impurities (impuritis), and is done manually or with scalping screens.

b. Crushing (crushing); with the aim of reducing size, using crushers, hammer mills, and roll mills.

c. Sizes; to sort the material based on the size according to market demand, which is done by using a sieve (screen).

d. Drying (drying); This is done if the material from the mine contains a lot of water, one of which can be done using a rotary dryer.

CHAPTER IV. POTENCY

Found Place

The presence of pumice in Indonesia is always associated with a series of Quaternary to young Tertiary volcanoes. Places where pumice is found include:

Jambi: Salambuku Lubukgaung, Kec. Bangko, Kab. Sarko (a fine pyroclastic material derived from volcanic rock or tuff with pumice components with a diameter of 0.5-0.15 cm in the Kasai formation).

Lampung: around the Krakatau Islands especially on Long Island (as a result of the eruption of Mount Krakatoa which spewed pumice).

West Java: Danu Crater, Banten, along the west coast (allegedly the result of the activities of Mount Krakatau); Nagreg, Kab. Bandung (in the form of fragments in tuff); Mancak, Pabuaran Kab. Serang (good quality for concrete aggregates, in the form of fragments in tuff and runoff); Cicurug Kab. Sukabumi (SiO2 content = 63.20%, Al2O3 = 12.5% ​​in the form of tuff rock fragments); Cikatomas, Cicurug, Mount Kiaraberes, Bogor.

Special Region of Yogyakarta; Kulon Progo in the Old Andesite Formation.

West Nusa Tenggara: Lendangnangka, Jurit, Rempung, Pringgasela (outcrop thickness 2-5 m spread over 1000 Ha): Masbagik Utara Kec. Masbagik Kab. East Lombok (thickness of outcrop 2-5 m spread over 1000 Ha); Tanah Beak, Kec. Batukliang Kab. Central Lombok (used as a lightweight concrete mix and filter); Kopang, Mantang Kec. Batukliang Kab. West Lombok (has been used for brick, 3000 ha spread); Narimaga District Rembiga Kab. West Lombok (outcrop thickness 2-4 m, has been cultivated by the people).

Maluku: Rum, Gato, Tidore (SiO2 content = 35.92-67.89%; Al2O3 = 6.4-16.98%).

CHAPTER V. APPLICATION

5.1 Utilization

Pumice is used more in the industrial sector than in the construction sector.

 In the construction sector

In the construction sector, pumice is widely used for the manufacture of lightweight aggregates and concrete. Aggregates are lightweight because they have very advantageous characteristics, namely light weight and soundproof (high in insulation). Pumice specific weight
of 650 kg/cm3 compared to ordinary bricks weighing 1,800 – 2,000 kg/cm3. From pumice it is easier to make large blocks, which can reduce plastering. Another advantage of using pumice in the manufacture of aggregates is that it is resistant to fire, condensation, mildew and heat, and is suitable for acoustics.

 In the industrial sector

In the industrial field, pumice is used as a filler, polisher, cleaner, stonewashing, abrasive, high temperature insulator and others.

Table 1. Industry users, functions, and degrees of pumice grain size:

Industry Usability Degree Size
Item

Paint – Coarse nonskid coating

  • Acoustic insulation paint
  • Coarse texture paint filler
  • Flattening agent Fine-coarse

Very smooth

Chemical – Coarse filtration media

  • Chemical carriers
  • Coarse sulfur match trigger

fine-coarse

Metals and plastics – Very fine cleaning and polishing

  • Vibratory and barrel finishing
  • Pressure blasting Very fine-medium
  • Medium Electro-plating
  • Glass or glass cleaner
    Fine
    Very smooth

Compounder – Medium hand soap powder

  • Glass or glass cleaner
    Very smooth

Cosmetics and toothpaste – Fine teeth polishes and fillings

  • even skin
    Liquid powder

Rubber – Medium Eraser

  • Mold material
    Very smooth

Skin – For medium shine

Glass and mirrors – Smooth TV tube processing

  • Smooth TV tube glass polisher and polish
  • Bevel finishing
  • Smooth glass cut Very fine

Very smooth

Electronics – Circuit board cleaner Very fine

Pottery – Smooth Filler

Description: coarse = 8 – 30 mesh; medium = 30 – 100 mesh; fine = 100 – 200 mesh; very fine > 200 mesh.

Source: Minerals Industry, Bulletin, 1990.

Pumice Media Filtration

As a filtration medium, pumice is widely used to clean urban and industrial waste. Because it has a large surface area and is highly porous, pumice is ideal for use as a filtration agent.

A growing body of research has shown buoyancy to be an effective medium for filtering drinking water. The foamy structure and near-whiteness of floating Hess make it ideal for capturing and retaining cyanobacterial toxins and other impurities that are found contaminating drinking water.

Pumice has several advantages over other filtration media such as expanded clay, anthracite, sand, and sintered PFA. Tests carried out on a comparison between bed sand and pumice filters for treating water found pumice to be superior in turbidity removal performance and head loss.

The benefits of pumice for water treatment applications include:

-Increased filtration rate
-low energy use
-as a good base mat in the filtration medium
-Larger surface area
-Low-cost filter maintenance
-Economical: saves on capital expenditure for new waste treatment plants

Beverage Filtration

The purification of ingredients and even the finished drink is important for taste consistency and quality. The same characteristics that make pumice a superior filtration medium for water also apply to beverages and other liquids. Pumice is non-toxic, completely inert and very versatile – it can be ground consistently against a wide range of specifications.

As a decorative lamp

In its development, pumice is widely used to decorate decorative lights. As has been done by Deddy Effendy, a craftsman from Yogyakarta, who uses pumice stone to beautify the design or model of his artificial bias lamp. The manufacturing process begins by cutting pumice stone with a chainsaw into 2-3 millimeter thick slabs with a length and width of about 10-15 cm.

The new buoyancy specifications are used.

Here are some examples of specifications for pumice used in the industrial sector:

a) For pigments are as follows:

  • Loss of glow : max. 5%
  • Flying substance : max. 1%
  • Passed 300 m filter : min. 70%
  • Passed 150 m filter : max. 30%

b) For pottery

  • SiO2 : 69.80%
  • Al2O3 : 17.70%
  • Fe2O3 : 1.58%
  • MgO : 0.53%
  • CaO : 1.49%
  • Na2O : 2.45%
  • K2O : 4.17%
  • H2O : 2.04%
  • Water content: 21%
  • Flexural strength : 31.89 kg/cm3
  • Water infiltration : 16.66%
  • Volume weight: 1.18 gr/cm2
  • Plasticity: Plastic
  • Grain size: 15 – 150 mesh

The composition of the material for this pottery consists of pumice, clay, and lime in a ratio of 35%, 60% and 5%, respectively. The use of pumice is intended to reduce weight and improve the quality of pottery. In addition to the construction and industrial sectors, pumice is also used in agriculture, namely as an additive and a substitute for agricultural soil.

FUTURE PROSPECTS OF PUMID STONE

Pumice Prospect

To be able to see the prospects for the Indonesian pumice mining industry in the future, it is necessary to review or analyze several factors or aspects that influence, both supporting and hindering. Because the data obtained were very limited, the analysis was only carried out qualitatively.

a. Influential Aspects

The development of the pumice mining industry in Indonesia, whether it has been, is being carried out or will be implemented in the future, is influenced by the following aspects:

Potential availability

The potential of Indonesian pumice scattered in the areas of Bengkulu, Lampung, West Java, Yogyakarta, West Nusa Tenggara, Bali and Ternate, cannot be known with certainty. But it is estimated to have reserves of more than 12 million m3. according to

Mining Service of NTB Province, the largest potential for pumice deposits is on the island of Lombok, West Nusa Tenggara, and its reserves are estimated at more than 7 million m3.

When viewed from the current production level, which is around 175,000 tons per year, the potential for pumice in Indonesia has only been exhausted for more than 40 years. However, the exploration and inventory of pumice deposits in the areas mentioned above needs to be upgraded to a more detailed exploration, so that the amount of reserves and their quality can be known with certainty.

Government policy

Aspects that are no less important for the mining industry are government policies, including the declaration of exports outside of oil and gas since Pelita IV, deregulation in the export sector, and increasing the use of natural resources. This policy is basically an incentive for exporters and entrepreneurs to invest, including in the pumice mining industry. However, in order for the government’s policy to be more successful, the pumice mining industry still needs to be accompanied by convenience in licensing and technical assistance, exploitation, as well as information about its potential; especially for entrepreneurs from economically weak groups.

Demand factor

With the development of the construction sector and the industrial use of pumice in developed and other developing countries, the demand for pumice has been increasing.

In the construction sector, in line with the increase in the population in the country, the need for housing continues to increase, which of course will increase the use of construction materials. For areas close to the location where pumice is found, and it is difficult to find bricks and tiles made of red earth, as well as stone for the foundation, pumice stone can be used as a substitute for this construction.

In recent years, the use of pumice stone for lightweight aggregates, namely roof tile, has been carried out by a building material company in Bogor, West Java and produces tile products that are lighter and stronger.

In developed countries, the use of lightweight and fire-resistant construction materials for the construction of buildings and housing is increasingly being prioritized. In this case, the use of pumice is very suitable because in addition to being light, it is also easy to handle, namely being formed into aggregates of the desired size so as to simplify and speed up the construction process. Likewise in developing countries, the use of pumice stone for the construction of housing that is easy and cheap and safe has begun to be widely practiced.

The increasing public interest in the use of jean-type textile materials, both at home and abroad, has spurred the jean-type textile industry to produce on a large scale, so that the use of pumice stone as stonewashing continues to increase.

Due to the advantages of the nature of pumice by using other minerals such as pumice compared to using other minerals such as pumice compared to using other minerals such as bentonite, zeolite, or kaolin, in developed countries, the use of pumice as a filler in pesticide industry, began to show an increase. If you use pumice, the pesticide will not sink in the water so it will work relatively more effectively, whereas if you use bentonite or kaolin, the pesticide will sink quickly and be less effective.

The availability of the above is evident from the level of demand (consumption and export) of limestone which continues to increase almost every year. In the pottery type ceramic industry, the use of pumice stone will improve the quality of the ceramic, which is lighter and stronger. However, the use of pumice for ceramic materials in the country is currently not widely developed and research is still being carried out.

Price factor

The current structure or trading system for pumice is still not profitable for pumice mining entrepreneurs. For example, in the West Nusa Tenggara area, in 1991 the price of pumice at the yambang location was around Rp. 450.00 – Rp. 500.00 per sack, and around Rp. 700.00 per sack. When finished, the dip roses will produce

net pumice stone about 30 kg/sack. Meanwhile, the price of pumice exported, if calculated from the value and volume of exports in 1991, obtained a price of Rp. 270.50 per kg. If the price is assumed to be the up to 40% price in the export destination country, transportation costs, taxes and insurance, as well as other costs of 40% of the price mentioned above, then the selling price of pumice stone at the exporter’s place is around Rp. 165.00 per kg, or Rp. 4,950.00 per kg.

Thus it is clear that the pumice at the mine site is very low. In other words, the pumice trading system in Indonesia tends to benefit exporters more than the mining entrepreneurs themselves. Therefore, there is a need for an overhaul in the pumice trading system in such a way, which can further support the improvement of the pumice mining industry, and still benefit all parties.

Substitution

In its use, pumice can be substituted with other materials. In the construction industry sector, pumice can be replaced by kaolin and feldspar as raw materials for roof tiles, waterways (culverts). For building walls, the use of pumice is competitive from red brick, asbestos, wooden planks, and so on. In the industrial sector, as well as raw materials in the ceramics industry, it can be substituted with bentonite, kaolin, feldspar, and zeolite which tend to be easy to obtain.

Other aspects

Other aspects that can affect the mining sector, particularly pumice mining, are:

a) Land overlapping problem.

In fact, there is a lot of potential for pumice found in plantations, forestry (protected forests and nature reserves), and other areas, resulting in a conflict of interest, which in the end tends to not be exploited.

can be used / cultivated.

b) Transportation problems

Although the price of pumice is relatively cheaper, because the transportation distance from the location where the pumice is located and the industries that use it is quite far, these industries tend to use other industrial minerals (substitutes).

c) Important information and technology utilization.

Basically, many investors are interested in the pumice mining industry. However, due to the lack of information on more accurate potential data, the investors continued their intentions. Likewise, research and information on technology for the use of pumice in the downstream industry for users, domestically still needs to be further improved, in order to support the development of the mining industry in the future.

b. Indonesian Pumice Stone Prospect

Based on an analysis of developments during the period 1985-1991 and the aspects that influenced it, the prospect of the Indonesian pumice mining industry in the future (until 2000) is estimated to be quite good.

c. Supply

Although there are substitutions of other materials for pumice and its use in the domestic industrial sector which has not developed much, if viewed from the side of the considerable potential, the increasing demand from abroad, as well as the government’s policy in exporting which is more flexible, it is estimated that the supply side is expected to be , namely the production and imports of pumice, will continue to increase.

 Production

Pumice production in the future is likely to be more influenced by domestic economic developments. Therefore, for the projection, the annual gross domestic income (GDP) growth rate is used; among others, 3%

(low projection), 5% (medium projection), 7% (high projection), then pumice production in 2000 is estimated to reach between 225,100-317,230 tons

Table 6. Projection of Indonesian Pumice Production in 1997 and 2000

Production on Projected Production (Tons)
1991
LP 1997 2000

Low (3.00 %) 194,200 225,100

172,554 Medium (5.00 %) 209,740 267,680

Height (7.00%) 225,100 317,230

Note: LP = Average growth rate per year

 Import

In line with the development of technology, in the future pumice refining in the country is estimated to be more advanced, and can produce products with specifications as required by the user industry. Thus, the import of pumice which originally arose as a result of its quality not being able to meet the downstream industry’s demand, can now be supplied from within its own country. Thus, in 2000 imports of pumice ceased to exist.

d. Request

Meanwhile, in line with the increasing need for construction materials that are lighter, safer and easier to handle, as well as increasing technological advances in the use of pumice in the industrial sector, the demand for pumice from inside and outside will continue to increase.

e. Consumption

Domestic consumption of pumice in recent years has begun to show an increase, especially in the construction sector. In the future, the consumption of pumice is expected to continue to increase. For the projection calculated by GDP growth rates of 3%, 5%, and 7%, it is obtained that the amount of pumice consumption in the country in 2000 was between 65,130-91,770 tons.

Table 7. Projected Indonesian Pumice Consumption in 1997 and 2000

Production on Projected Production (Tons)
1991
LP 1997 2000

Low (3.00 %) 56.180 65.130

49,917 Medium (5.00 %) 60,670 77,440

Height (7.00%) 65,430 91,770

Note: LP = Average growth rate per year

f. Export

Export projections to meet demand from other countries in 2000 are estimated to reach between 184,770-369,390 tons (Table 3).

Table 8. Projection of Indonesian Pumice Exports in 1997 and 2000

Production on Projected Production (Tons)
1991
LP 1997 2000

Low (3.00 %) 119.480 138.510

106,161 Medium (5.00 %) 139,150 164,690

Height (7.00%) 184.770 369.390

Note: LP = Average growth rate per year

CHAPTER VI

PUMUM STONE WASTE

Pumice, which is widely found in several regions in Indonesia, has many uses and has been widely used by the people of Indonesia, and has even become a commoditive material for Indonesian exports to foreign countries. There are also many pumice grinding or refining factories in Indonesia, especially in areas of potential for pumice excavation. The pumice waste generated from the refining process is not utilized by the local community, causing the community’s productive land to be reduced because it is used as a dumping ground for pumice waste.

Definition of pumice waste

Pumice waste is the result of the pumice sieving process that is no longer used because the amount is less than packing requirements to be marketed (size of pumice waste aggregate ranges from 0.1mm – 1cm).The process of formation of pumice waste.

Pumice waste comes from pumice processing factories which is the remnants of pumice itself and cannot be marketed to consumers because of its irregular shape and gradation smaller than 1 cm. Pumice waste is almost like sand and gravel in general, only the unit weight is lighter and it is porous that distinguishes it from ordinary gravel. Because of its lightness, pumice waste is very good to be processed into building materials that have a light weight.

Utilization of pumice waste

Pumice waste can be used as:

As a substitute for class C excavation building materials

Reducing the use of productive land that is used as a dumping ground for pumice waste.

Increasing people’s income by creating new job opportunities by utilizing pumice waste that is no longer used.

Negative impact of pumice mining in Lombok, NTB

In addition to having a positive effect in the form of several uses, pumice also has a negative impact on the environment and society. Especially seen on the island of Lombok, NTB.

Overall it can be said that there has been a decline in soil fertility due to mining. The decrease in macronutrient content (N, P, K), organic C, and CEC values ​​(Cation Exchange Capacity) was caused by the removal of the top soil layer and the appearance of a coarser textured bottom layer. As a result of the demolition and removal of the top layer, the former pumice mining soil contains a larger fraction of sand than the unmined soil. Based on the rating criteria proposed by PPT Bogor (1983), the physical properties of the former pumice mining soil have unstable aggregates, very high porosity and very fast permeability. The reversal of the soil layer will be very detrimental to post-mining plant growth. Degradation of soil structure as a result of dismantling the tillage layer will result in more susceptibility of the soil to erosion, a decrease in the ability of the soil to hold water (water holding capacity) and can accelerate the loss of nutrients in the soil.

Level of land damage due to pumice mining

The level of land damage due to mining of pumice-C excavation is approached by looking at several factors: excavation depth, mining area, land slope, presence of vegetation and post-mining conservation activities. Based on the score used, the level of land damage (heavy, moderate and light damage) varies at each mining site. In the center of pumice mining in West Lombok, about 34% were heavily damaged, 61% were moderately damaged and 5% were lightly damaged. In Central Lombok, about 20% were heavily damaged, 75% were moderately damaged and 5% were lightly damaged, while in East Lombok Regency it was around

12% heavily damaged, 80% moderately damaged and 8% lightly damaged. The heavy damage was caused by deep excavation (>3m), steep slopes (>20%), and the absence of post-mining conservative land management efforts.

Deep excavations (>3m) were found at several mining sites in northern and central Lombok. Digging of 1.5 – 3 meters is the most dominant digging depth in all locations. Deep digging (>3 m) on sloping land (>20%) and cliffs caused the most damage, although the extent of damage was relatively narrow. Shallow excavation on flat land but without any post-digging revegetation will also spur land damage in the next stage. The increase in the area of ​​mining land has implications for the extent of land damage that occurs, which of course will have implications for the increased cost of land restoration required. Mining carried out on land with a slope of >20% is found in several places, namely in North Lombok, Batukliang, and Pringgasela. The most dominant slope of the mining area in all locations ranges from 6 – 10%.

Of all the observed mining locations, it turns out that most of the post-mining land management efforts have not been carried out. In other words, most of the former mining areas are still abandoned without any rehabilitation efforts. In addition to the three aspects discussed above, the area of ​​the mining area also plays an important role in creating an image of the level of land damage. Mining areas with an average area of ​​>15 ha are found in North Lombok. Mining areas with an area of ​​between 6-10 ha are mostly found in North Lombok and several locations in Kec. Masbagik East Lombok. Mining area between 1-5 Ha is the most common area found in all mining locations.

CHAPTER VII. CLOSING

Pumice is formed from volcanic eruptions. Pumice or pumice is a type of rock that is light in color, contains foam made of bubbles glass-walled, and is usually referred to as silicate volcanic glass rock. These rocks are formed from acidic magma by the action of volcanic eruptions which release the material into the air and then undergo horizontal transportation and accumulate as pyroclastic rocks.

Pumice has high nersicular properties, contains a large number of cells due to the expansion of the natural gas foam contained therein. It is generally found as loose material or fragments in volcanic breccias. While the minerals contained in pumice are feldpar, quartz, obsidian, cristobalite and tridymite. One of the potential minerals for Gol C in West Lombok is pumice, its presence is spread in several sub-districts, especially in the northern part of West Lombok, such as Bayan, Gangga, Kayangan sub-districts, some in the middle, namely Narmada and Lingsar sub-districts. Its existence is as a result of the activity of the Rinjani volcano which is rich in silica and has a porous structure that occurs due to the release of gases in it at the time of its formation.

In West Lombok, there are at least 20 pumice processing companies spread across various regions. Pumice in West Lombok is an export commodity, especially to China as an ingredient in textile washing. In general, pumice is also used as a abrasive, lightweight and fire-resistant building material, as a filler for high, low and acoustic insulators, as an absorbent and filter material. Currently, pumice mining in West Lombok is reaping many problems, especially environmental problems, where most of the mining is carried out without a permit and does not pay attention to environmental sustainability.

BIBLIOGRAPHY

Fadillah, Said. 2005. Mining AMDAL Training Module. Jakarta: The Ministry of Regional Development is lagging behind Sukandarrumudi. 2009. Industrial Minerals. Yogyakarta: UGM Press.

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