Vermiculite - what is it? Vermiculite for plants

On the shelves of garden shops, packaging with the inscription "Vermiculite" appeared for a long time. Most gardeners and truck farmers, as well as ordinary citizens, do not know what kind of material it is and why it is needed. So, vermiculite - what is it and where it is used? We will try to answer this question in the article, and also to tell in detail about how and from what it is received, and about the possibilities of using this mineral.

What is this material?

Natural vermiculite is a natural mineral from the group of hydromica, formed as a result of leaching and weathering of biotite mica. Outwardly it looks like a plate-like crystal of a yellowish-brown color. But after heating it to a temperature of 900 ° C it turns into vermiculite swollen. His plates look like sticks, something reminiscent of worms, which was reflected in the name, because from Latin to Russian, vermiculus is translated as "worm, worm-like."

Physico-chemical characteristics

Vermiculite, found in nature, can be painted in silver, golden, brown, green and black. It contains oxides of silicon, iron, calcium, potassium, magnesium and other microelements. In addition, it does not contain heavy metals and any toxic components, nor does it react with alkalis and acids. Due to this, vermiculite for plants is widely used both in decorative floriculture and in horticulture.

It is also important that this mineral is not susceptible to decay and decomposition under the influence of natural and biological factors. Because of this, various microorganisms, insects and animals in it do not settle.

It is worth emphasizing, speaking about vermiculite, that this is a highly porous material with excellent moisture-absorbing properties. The water absorption coefficient of this mineral is 400%. This means that 100 g of vermiculite can absorb 400 ml of water.

Thus, this natural mineral has the following properties:

• Ecological compatibility;
• durability;
• Chemical and biological inertness in interaction with corrosive media;
• Low thermal conductivity;
• High fire resistance;
• Low density.

Where do they get it?

This natural material was accidentally discovered in the 19th century, and since then it has been exploring and mining. As already mentioned, vermiculite is a mineral that has deposits in Russia - in the Krasnoyarsk Territory, the Kola Peninsula, Irkutsk and Chelyabinsk regions, and in the near abroad: in Kazakhstan, Uzbekistan, Ukraine. In addition, it is mined in Australia, India, South Africa, Uganda and the United States. In the state of Montana, near the town of Libby, is the largest and most profitable American deposit of this mineral.

How Recycling Works

Extracted vermiculite is subjected to special treatment in concentrating plants. There, the mica is sorted and sorted, some of which is then sent to the electrotechnical industry, and the remaining hydrothermal process is processed in conveyor furnaces at a temperature of about 760 ° C. As a result of this action, individual mineral particles are stratified and swollen, and vermiculite is expelled at the outlet. In the process of further processing, the resulting mass is ground to a predetermined value.

Features of expanded vermiculite

As already mentioned, this natural mineral undergoes industrial processing by roasting, during which it significantly increases in volume and separates into worm-like particles. Such a change is due to water, which is in the structure of vermiculite in a bound state. Under the influence of high temperatures, it heats up and converts to steam, which pushes and cleaves the mica plates, thereby increasing the volume. Thus, one can speak about expanded vermiculite, that it is a "burnt" mineral with a modified structure.

What are the fractions?

Crush this mineral to different fractions, which are classified according to the size. In total, there are 5 groups, where 1 is the largest, the size of a small coin, and 5 is a suspension that resembles dust or fine sand. Unmilled vermiculite - a heater, widely used in construction for backfilling in hollow panels.

In floriculture and plant growing, vermiculite from 2 to 4 fractions is usually used. This material in a dry form is quite light, but after moistening its weight increases almost 5 times, due to absorbed and retained water.

Applications

Open relatively recently, a mineral such as vermiculite, and its derivatives have found many different uses today:

1. Ecology, oil and chemical industries. Few can answer when asked about vermiculite, that it is an excellent sorbent, capable of binding alkalis and acids. This property allows it to be used to neutralize a variety of chemicals in production, as well as to limit oil spills.
2. Nuclear industry and energy. Used as an absorber of such radioactive elements as cobalt-58, strontium-90 and cesium-137, and also as a reflector of gamma radiation.
3. Automotive and aviation industry. Manufacture of various vermiculite sound-absorbing and heat-insulating materials and products.
4. In industrial and civil construction, vermiculite is used as follows:

• Insulation, as well as sound and heat insulator for roofs and floors;

• For backfilling as a thermal insulation material in hollow panels;
• As a component of various plasters, lightweight concrete and dry building mixtures;
• In the manufacture of concrete and cement blocks, as well as heat-insulating mastics as a filler;
• In the production of flame retardant and heat-resistant boards, panels and other wall materials;
• At arrangement of self-leveling floors.

5. In industrial and private plant growing and gardening. Let's consider in more detail how vermiculite for plants is used.

Features of use in plant growing

This mineral, which has undergone industrial treatment, is widely used at all stages of plant growth and development:

• With the germination of seeds and for the rooting of cuttings, which are not affected by various microorganisms - pathogens and fungi, and also receive all the necessary nutrients and microelements;
• To create various soil mixtures and give them the necessary looseness and porosity;
• When growing hydroponic crops;
• As a drainage layer with a variety of planting both potted and garden plants;
• For mulching landings;
• For winter storage of various bulbous and bulbous cultures: vermiculite not only maintains a normal temperature and gas regime, but also prevents damage to planting material by various diseases and pathogens;
• In the process of creating a compost.

Speaking of which, vermiculite - what is it, what it is needed for, it is worth recalling a few simple rules that must be observed when working with it:

1. The used material can be used repeatedly, but only after obligatory calcination.
2. Since it absorbs a lot of water and gives it to plants for a long time, it should be remembered and do not allow excessive watering, which can lead to waterlogging of the soil and death of plants.
3. Two mineral substances - perlite, vermiculite - have similar properties, which allows them to be used together when growing plants.
4. It is important to remember that vermiculite interacts with hard water and can "move" the acidity of the soil to the alkaline side. That's why most experts recommend using pure vermiculite only for germination of seedlings or when working with hydroponic crops, when the qualitative composition of water is known and constant.