Silica-Sustainable Benefits and Impacts

Silica, also called silicon dioxide, combines Silicon and Oxygen, SiO2. It is a common mineral found in the crust of the earth, and it can be seen in stone, soil, sand, concrete, brick, mortar, and other construction materials. Non-crystalline Silica can be found in glass, silicon carbide, and silicone and these are much less hazardous to the lungs. In the case of Crystalline Silica, it comes in different forms, and Quartz is the most common form of crystalline Silica. Workers’ exposure to respirable crystalline Silica is associated with elevated lung cancer rates. Silica has vital benefits and impacts the whole environment, including human beings, animals, plants, water and air.

Benefits of Silica on the human body

As per some of the research, Silica has many benefits for the human body. It is a trace mineral integral to connective tissue’s structure and functional integrity and a common health supplement that aids in the development of bone, skin, and nails.

  • It supports bone formation and maintenance.
  • Helps to make collagen
  • Helps to protect heart health

Benefits of Silica in Industries

Silica has widespread industrial benefits, including its use as a food additive, as a means to clarify beverages, dough modifier, as an excipient in drugs and vitamins etc. It has a variety of application in many industrial purposes, from construction to chemicals to glass and for common products like plastic, paint, rubber, personal care products, electronics etc. Silica gel is not a gel; it can absorb water and other liquids instead of dissolving. That’s why it is used in food packets, shoe boxes, and dirty laundry in toolboxes to absorb moisture. Some of the industries are;

  • Glassmaking

All standard and speciality glasses comprise silica sand as the primary component. SiO2 component helps glass formulation, and its chemical purity is the primary determinant of colour, clarity and strength.

  • Metal casting          

Silica sand is the most commonly used type of foundry sand. This sand was used in core making, so switching to using the same aggregate in the complete casting process made managing foundry supplies easier.

  • Personal care products or Cosmetics

Silica is common in cosmetic and skincare products because it can change the feel and texture of the product. Silica act as an absorbing agent, anti-caking agent, bulking agent, suspending agent etc.

Benefits of Silica for the environment and Plants

In relation to Silica, plants can categorizes into three types: accumulators, intermediaries and non-accumulators. These categorization mainly depends on the extent to which Silica accumulates in the plant’s tissue. 

Accumulators have the highest accumulation rate, and the most significant benefits have been tied to these plants. Non-accumulator plants also positively respond to the use of silicas in fertilization. Silica consider to be a quasi-essential nutrient for most plants. Some of the benefits are;

  •  Increases plant tolerance to drought, frost and lodging
  •  Increased resistance to abiotic stress
  •  Increased resistance to biotic stress

SILICA IN AIR, WATER AND HEALTH EFFECTS

Environmental effects of Silica in air

Exposure to silica dust will cause various health problems among people. This will be a more serious issue for workers who work in environments that contain silica dust since inhalation of such dust will irritate the lungs and mucus membranes. 

Environmental effects of Silica in water

Keeping aside the fact that Silica’s presence in water is generally harmless since it is naturally present in larger amounts. But an abnormal level of Silica in water will limit the algal growth in the water bodies. Moreover, zeolite, a phosphate replacement in detergents affects the water organisms. Thus, concentrated levels of Silica in water will alleviate the plant water status and water balance in both monocot and dicot plants, mainly under drought and salt stresses. 

Health risks of exposure

Breathing in silica dust will often result in silicosis because when these dust particles gets into the lung tissue, it causes inflammation and scarring, eventually reducing the lung’s ability to breathe in the required amount of oxygen into the human body. This condition is commonly referred to as ‘silicosis’. Thus, silicosis results in permanent lung damage that might be progressive, debilitating and even fatal. Cough, fatigue, shortness of breath, and chest pain are common symptoms. Ten or more years of continuous exposure to crystalline Silica will result in chronic silicosis. 

Till now, there is no cure for silicosis, and some patients might require lung transplantation. Often, workers get more exposed to Silica, causing an increased risk of tuberculosis. 

Following are the other serious health effects resulting from increased exposure to crystalline Silica in workers;

  • Lung cancer happens when cells in the body grow out of control and become tumours. Cancerous cells from the body can spread to other parts of the body resulting in metastasis.
  • Chronic Obstructive Pulmonary Disease (COPD): This includes chronic bronchitis and emphysema with symptoms like shortness of breath, coughing, sputum production etc. 
  • Kidney disease: Various studies among workers have stated that increasing levels of silica exposure for a larger period will increase the risk of chronic kidney diseases among workers.
  • Autoimmune disease: Studies among workers also show that increased silica exposure increases the risk of autoimmune diseases like rheumatoid arthritis, systemic lupus erythematosus and systemic sclerosis.

Silica has a wide application in medicine, textile, cosmetics, construction, and other industries too. The researches are undergoing for the further applications of Silica on the human body. Silica has both benefits and negative impacts on the environment, and it can lead to growth and put nature at risk.

Crystalline Silica

Where does crystalline silica come from?

Some examples of everyday crystalline silica-containing products include abrasive blasting materials, cement, bricks, mortars, plasters, patching materials for asphalt, caulking compounds, roofing materials, concrete construction products, such as concrete blocks and pavers, fill, and decorative stones. Silica formation happens during cutting, sawing, grinding, drilling, and crushing stones, rocks, concrete, bricks, blocks, and mortar. The respirable crystalline silica is much smaller than ordinary sand on beaches and playgrounds. For the complete combustion of rice husks after acid leaching, an air supplement of 50 mL/min or more was necessary to provide sufficient air. Silica materials with a purity of 99 wt% or more were prepared from rice husks using a variety of processes.

Worker exposure to crystalline silica dust occurs during harsh blasting with sand, sawing brick or concrete, drilling into concrete walls, and grinding mortar. Similarly manufacturing bricks, stone countertops, ceramic commodities, and cutting or crushing rock also release silica. Known sources of crystalline silica exposure include foundry sand and hydraulic fracturing (fracking). 

Crystalline silica and its Impacts on life

By breathing in crystalline silica dust, you can develop silicosis. Black lung disease and coal workers’ pneumoconiosis, due to dust inhalation, are other types of pneumoconiosis.

Silicosis starts with simple inflammation and then leads to pulmonary fibrosis. Silica exposure can affect the nose, throat, and lungs , which may cause coughing spells or shortness of breath.

The effects of crystalline silica dust on the respiratory system may leads to allergic sensitization.

Other health effects can cause lung cancer because of its highly radioactive properties. Exposure to silica has link with developing cancers like stomach cancer and other solid tumours.

 Crystalline silica products pose health risks.

Cristobalite products can cause extreme toxicity as they can easily penetrate bodily tissues and organs due to their acute toxicity. 

High exposure to crystalline silica dust results in acute health effects. Shortness of breath, irritation in the eyes and nose, throat infection and tiredness are some among them.

In extremely high concentrations, silica can cause asphyxiation by preventing oxygen from reaching vital organs. This is why silica dust threatens both environmental and human health.

Effects of Silica dust on Animal life 

Silica dust may affect respiratory tract problems in animals exposed to it. Silica particles are more likely to be ingested by cats, horses, cattle, and pigs since they often chew on objects.

Effects of Silica dust on plants and wildlife

Abrasion of leaves caused by crystallized silica dust reduces photosynthesis, decreases seed production, inhibits seedling growth, and increases resistance to diseases and pests. Soil impurification by silica can make it challenging for plants to grow, affecting the food chain since carnivores hunt prey that eats plants.

Plants may have difficulty absorbing nutrients if microbial activity in the soil is reduced. It affects plant growth by lowering photosynthesis, promoting disease, and inhibiting growth.

The long-term inhalation, ingestion, or absorption of crystallized silica dust significantly affects amphibians, resulting in their death. 

Effects of crystalline silica on the environment

Silica dust settles on plants, soil, rocks, and other surfaces nearby, so its effects are more excellent near the ground. Silica particles can also be spread by wind to a far distance from the initial source of contamination.

Crystalline silica dust has more significant toxicity to those species that live adjacent to the soil. Those species mainly include earthworms and small mammals. Due to its tendency to settle in coastal areas with highly contaminated soils, silica dust can also affect aquatic organisms.

Soil impurification by silica can make it challenging for plants to grow, affecting the food chain since carnivores hunt prey that eats plants. Crystalline silica dust damages insects, worms, and other tiny organisms too.

 What can be done to reduce the release of crystalline silica dust into the atmosphere?

We can reduce the environmental impact of crystalline silica dust by minimizing soil erosion, establishing wind barriers to lower emissions, planting vegetation buffers to absorb dust particles before they enter the atmosphere, applying binders to soils before construction, disposing of crystalline silica dust correctly, and eliminate plastic waste used during mining.

 

There is already a global supply squeeze on silica sand. Since the populations within the developing world continue to rapidly urbanize, the demand grow significantly every year. As supply sources dwindle, miners increasingly source silica sand from vulnerable ecosystems and waterways.

There are well-documented environmental impacts of silica sand mining in marine and riverine systems. It leads to erosion, salination of aquifers, loss of protection against storm surges, and impacts on biodiversity. These threaten livelihoods through adverse effects on water supply, food production, fisheries, and tourism.

With the rapid urbanization of the global population, it requires enormous volumes of sand per year to keep up with current demand. Concrete and glass for construction projects are not the only uses for silica sand, it also has a crucial role in the global decarbonization effort. For the high-tech glass of solar panels and bright screen technology needs high-purity silica sand with low iron content. During the next few decades, the demand for ultra-clear glass expects to grow exponentially as Asia-Pacific region mainly adopts solar panels.

Conclusion

In some circumstances and in some forms, silica can be detrimental to the environment, but it can also be beneficial. Despite of all harmful effects of crystalline silica by implementing advanced techniques silica has many applications paving roads, glass making, foundries etc. There are potentially hidden ecological costs associated with improper harvesting of silica.

In conclusion, silica is naturally found in our environment, and what makes it worse are the unforeseen environmental impacts of harvesting them.

Global Demand for Silica

Silica is a chemical compound in different forms, like sand, soil, quartz, and crystalline silica. It is the major ingredient in many industries. And sometimes, it is also found in the human body at a low or high level. A wide range of silica producers and consumers with various consulting engagement results in increased global demand for silica.

Silica occurs in nature in the form of crystalline silica, also known as quartz. This crystalline silica is extraordinarily sharp and fragile. When these crystals shatter, they actually fragment into tiny dust particles, which easily get into the body of humans or animals while respiration. The smaller the fragments produced, the more threat it will be, to the environment and living things around. 

Some of the important uses of silica are:

  • Production of glasses
  • For Sandblasting and making sandpaper 
  • Various types of dishes like glasses and cups.
  • Adhesives glue 
  • Production of many toothpastes 

Silica sand, generally called industrial sand, is the main common variety globally. It was mining for many years and was first put to industrial use even during 3000-5000 BC for metallurgical and glass-making activities.

The key factors driving the global demand for silica :

The increasing uses of silica sand in paving roads, glass making, foundries and coal burning boilers, oil and water filtration, industrial casting, sandblasting, etc., is now catalyzing the global silica sand market.

Additionally, it has an important application in the hydraulic fracturing, where the order for silica sand is increasing significantly in recent years. This can be certified to the profitable qualities of silica sand, like strength, high silica content, and resistance to heat and chemical reactions.

Khaitan Responsibly sources silica sand to meet global demand

Global stocks of silica sand are being used up rapidly than they are being discovered. As the main ingredient for all glass and concrete, silica sand is the basic ingredient of today’s world. The UN estimates that the world currently uses 50 billion tonnes or more of it to construct a wall 27m wide and 27m high around the planet – every year.we extract Silica as a high value byeproduct and valorize lignin to generate steam. This is a major breakthrough in establishing commercial viability for the technology and compete with ethanol produced from other sources.

Oil and gas industries fuel silica markets

Silica consists of the earth crust’s most abundant elements: silicon and oxygen. Silica has various crystalline forms, such as fibrous, granular, anhydrous, tridymite, cristobalite, and quartz. Quartz is the next most mineral found in the earth’s crust.  

Silica deposits undergo extensive processing before the sale, including cleaning, washing, scrubbing, melting, and grinding to remove impurities and to produce the ideal size distribution of product depending upon end–use. Silica has many end-users and applications across various industries.   

The energy sector is one where increased exploration and production for oil and gas have increased the demand for silica used in the past decade. In hydraulic fracturing, it is widely used as a proppant to hold open fractures to allow oil and gas. Also to flow out of the production and into the excellent bore. Figure 1 shows the United States consumed 100 million tons of industrial sand and gravel in 2017, an increase of 33% from the previous year. This increase was primarily due to increased activity in the oil and gas industry. 

Figure 1: End-uses of silica sand consumption in 2017.

 

In addition to hydraulic fracturing for oil and gas production, silica serves in many other industries too. Depending upon the types of silica, the uses varies. Following are the few of the major applications  

  • Glass: glass containers, flat glass, automotive glass, fibreglass, and speciality glass 
  • Construction: flooring, roofing, mortars, and speciality blocks of cement 
  • Ceramics: glossier products and applications that need good thermal resistance
  • Foundries: highway and construction use, aggregate substitutes, and manufactured soils
  • Chemicals: Polymers, personal care products, industrial cleaners, fibre optics 

Global Silica Sand Industry Drivers:

  • The glass market is facing high growth as a result of increased demand from the construction industry, increasing automotive production or sales, mounting per capita income, and technological improvements. Along this, rising trends such as increasing usage of the hybrid guide plate, solar powered glazing for automotive and building glasses, flimsy glazing glass, and new launch of flat glass are also contributing towards the extension of of the glass industry boosting the demand for silica sand.
  • Several countries worldwide prefer natural shale gas to reduce their dependence on crude oil. In Shale gas extraction using the hydraulic fracturing process where silica sand is the proppant. As a result, the growth in shale gas production is a reason to widen the demand for silica sand. 
  • Upcoming industrial projects in different nations expects to accelerate the manufacturing industry, thereby adding up the need for silica across different sections. Tour Triangle and the ASVEL arena(France) are forecasted to support the silica sand market growth.

 

Key Market Segmentation:

Based on end-use, the record discovers that the glass industry considers more than a third of the total market, constituting the largest end-use sector. Silica sand is essential in producing glass containers, flat glass, and speciality glass that further use in automotive, construction and solar applications. The glass industry followed by foundry, hydraulic fracturing, filtration, and abrasives.

Regional Insights:

  • China
  • United States
  • Italy
  • Turkey
  • Germany
  • Australia
  • Others

Region-wise, the China enjoys the leading position in the global silica sand market. China is followed by United States, Italy, Turkey, Germany, Australia and Others.

With such vast uses of silica in various industries, silica demand continues to increase globally. Each of these applications requires silica with a specific set of properties and compositional requirements.

Silica

Silica is also known as silicon dioxide, a chemical component found in sand, gravel, clay, granite, and other rock types. It is a dense and intricate substance comprised of silicon and oxygen, the two most prevalent elements in the earth’s crust. It is the principal component of most types of sand and a critical part of glass-making. Making glass items out of silica is a centuries-old craft with a wide range of modern industrial applications. These include abrasives, construction supplies, fillers, electronics, and water filtration.

Properties

  • The chemical and physical features include hardness, colour, melting and boiling points, and reactivity.
  • It is a solid, crystallised mineral at standard temperature and pressure conditions. It is relatively hard, scoring a 7 on the Mohs scale, which compares the hardness of minerals. Diamond, the hardest mineral, is a 10 on the scale.
  • Pure silica is colourless. However, quartz may appear coloured if impurities are present. Rose quartz, for example, is silica with traces of iron. Because of this, it appears pink. Silica containing liquid or air bubble inclusions, known as milky quartz, gives the crystal a white appearance.
  • It has extremely high melting and boiling points: 3,110 °F and 4,046 °F, respectively. E.g. Silica sand is melted in a large, hot furnace to manufacture glass.
  • It reacts with hydrofluoric acid, used in the semiconductor industry to carve quartz.
  • It also reacts with metal oxides such as sodium oxide and lead oxide. These reactions create several glass forms, such as borosilicate and leaded glass. Borosilicate glass is a form that withstands temperature fluctuations, used in laboratory glassware.

Types

Crystalline Silica

The chemical term of this type is silicon dioxide (SiO2). Numerous rocks (sandstone, granite, sand) contain various proportions of crystalline silica, mostly quartz. Sand is a source of crystalline silica since it is almost entirely comprised of quartz. The existence of crystals can be seen on a small scale because It has a 3-dimensional structure that creates crystalline domains.

Found in – It is a natural material found in stone, soil, and sand and is also present in concrete, brick, mortar, and other construction materials.

Subtypes – There are three primary forms of crystalline silica in the earth’s crust: quartz, cristobalite, and tridymite.

Benefits & Uses

It has many industrial uses, including as an excipient in pharmaceuticals and vitamins, as a food additive (i.e., an anti-caking agent), as a way to clarify liquids, control viscosity, as an anti-foaming agent, and as a dough modifier. Also, have a use case to construct glass, pottery, ceramics, bricks, and artificial stone.

Risks

Inhalation is the principal route of exposure to crystalline silica. Because, at first it must be ground or crushed before utilising as an absorbent, granulation, or filler in building materials. At this point, it would be processed to create tiny particles. Once inhaled, these small particles can cause various illnesses or bodily dysfunctions, the most serious of which are silicosis and lung cancer.

Exposure to silica particles when cutting, grinding, drilling, sanding, combining or demolishing silica-containing materials of construction workers results in long-term harm. The amount of risk determined by the size of the airborne silica particles. Smaller particles breathed deeply into the lungs could cause long-term damage. Larger particles, such as beach sand, are less of an issue because they are too big to inhale.

Non-crystalline silica

Amorphous silica is another name for non-crystalline silica. The term “amorphous” refers to the lack of a defined shape or form and the fact that it is not a salt crystal. Amorphous silica gel is a white powder with a fine sand-like texture, and it has a silvery sheen to it.

Found in – Commonly found in glass, silicon carbide, and silicone.

Subtypes – It can be natural or manufactured, anhydrous or surface-hydrated containing silanol groups. Micro amorphous silica and vitreous silica (glass) are synthetic amorphous silica.

Benefits & Uses

There are numerous beneficial qualities for manufacturing a wide range of valuable products. One of the properties includes the ability to absorb and filter water. Because of its propensity to absorb moisture from the air, silica gel has been employed as a desiccant in those small bags that are usually found in products to guard against excess moisture. A different form of amorphous silica acts as an agent in toothpaste, cosmetics, food packaging, and food additives.

Risks

Exposure to amorphous silica in quantities prevalent in the environment or industrial items like cosmetics has no known negative impact on health. It may cause respiratory illnesses in employees (although not silicosis, according to a few reports). Studies on lab animals show that inhaling amorphous silica is less dangerous than crystalline silica, despite the possibility of lung irritation and damage.