REFRACTORIES - Bricks and shapes are the more traditional form of refractories. Refractories are produced from natural and synthetic materials, usually nonmetallic, or combinations of compounds and minerals such as alumina, fireclays, bauxite, chromite, dolomite, magnesite, silicon carbide, and zirconia. Refractories can withstand physical wear and corrosion caused by chemical agents. From the simple (e.g., fireplace brick linings) to the sophisticated (e.g., reentry heat shields for the space shuttle), refractories are used to contain heat and protect processing equipment from intense temperatures.

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Refractories

What Are Refractories?

The Refractories Institute

Refractories are ceramic materials designed to withstand the very high temperatures (in excess of 1,000°F [538°C]) encountered in modern manufacturing.

More heat-resistant than metals, they are used to line the hot surfaces found inside many industrial processes.

In addition to being resistant to thermal stress and other physical phenomena induced by heat, refractories can withstand physical wear and corrosion caused by chemical agents.

Thus, they are essential to the manufacture of petrochemical products and the refining of gasoline.

Refractory products generally fall into one of two broad categories: preformed shapes or unformed compositions, often called specialty or monolithic refractories.

Then, there are refractory ceramic fibers, which resemble residential insulation, but insulate at much higher temperatures.

Bricks and shapes are the more traditional form of refractories and historically have accounted for the majority of refractory production.

Refractories come in all shapes and sizes. They can be pressed or molded for use in floors and walls, produced in interlocking shapes and wedges, or curved to fit the insides of boilers and ladles.

Some refractory parts are small and possess a complex and delicate geometry; others, in the form of precast or fusion-cast blocks, are massive and may weigh several tons.

What Are Refractories Made Of?

Refractories are produced from natural and synthetic materials, usually nonmetallic, or combinations of compounds and minerals such as alumina, fireclays, bauxite, chromite, dolomite, magnesite, silicon carbide, and zirconia.

What Are Refractories Used For?

From the simple (e.g., fireplace brick linings) to the sophisticated (e.g., reentry heat shields for the space shuttle), refractories are used to contain heat and protect processing equipment from intense temperatures.

In industry, they are used to line boilers and furnaces of all types (reactors, ladles, stills, kilns, etc.).

It is a tribute to refractory engineers, scientists, technicians, and plant personnel that more than 5,000 brand name products in the United States are listed in the latest “Product Directory of the Refractories Industry.”

Established in 1951 and headquartered in Cleveland, Ohio, The Refractories Institute (TRI) has a long tradition of providing support and services to manufacturers of refractory materials and products and suppliers of raw materials, equipment, and services to the refractories industry.

In 1995, membership eligibility was extended to refractories producers in Latin America. In 1996, the institute’s board of directors voted to open membership to contractors and installers of refractory products, recognizing the important role they play in ensuring the ultimate success of a product.

TRI currently is comprised of 48 member companies, 24 of which are manufacturers of refractory products.

https://www.refractoriesinstitute.org/tri-pages/tri-what-are-refractories.asp

CHLORINE BLEACH SHELF LIFE - According to Clorox™, the amount of hypochlorite that is added to their bleach depends on the season in which it is manufactured, because temperature affects the decomposition rate of sodium hypochlorite. So, more hypochlorite is added to bleach made in the summer than in cooler months. Clorox aims to maintain a 6% hypochlorite concentration for at least six months after the manufacturing date, assuming the bleach is stored around 70°F. It takes about 4-8 weeks from the time chlorine bleach is made to when it gets to a store so that you can buy it to take home. This leaves you 3-5 months where the bleach is at the effectiveness level stated on its label.

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Chlorine Bleach Shelf Life

How Long Is Bleach Good?

by Anne Marie Helmenstine, Ph.D.

Bleach is one of those household chemicals that loses its activity over time. It doesn't matter whether or not the bleach container has been opened or not.

Temperature is the primary factor affecting how long bleach remains active.

According to Clorox™, the amount of hypochlorite that is added to their bleach depends on the season in which it is manufactured, because temperature affects the decomposition rate of sodium hypochlorite.

So, more hypochlorite is added to bleach made in the summer than in cooler months. Clorox aims to maintain a 6% hypochlorite concentration for at least six months after the manufacturing date, assuming the bleach is stored around 70°F.

It takes about 4-8 weeks from the time chlorine bleach is made to when it gets to a store so that you can buy it to take home. This leaves you 3-5 months where the bleach is at the effectiveness level stated on its label.

Does this mean bleach is useless after 3-5 months? No, because you probably don't need 6% hypochlorite for laundry and home disinfection.

The 6% hypochlorite level is an EPA disinfection standard. If you store your bleach where it can get warmer than 70°F, like 90°F, the bleach is still effective for around three months.

How Long Is Bleach Good?

So, when you buy a bottle of bleach, it has a shelf life. The bleach will be highly effective for around 6 months and fine for home use for around 9 months. Clorox recommends replacing any bottle of bleach that is over a year old.

Another way to tell if your bleach is expired is to note its odor. Don't open the bottle and take a whiff!

The human sense of smell is sensitive to bleach, so you should be able to smell it as soon as you pour it from its container. If you don't smell any bleach, it's likely most of the product has decomposed into salt and water. Replace it with a fresh bottle.

Maximizing the Bleach Shelf Life

If you want bleach to remain as effective as possible for as long as possible, avoid storing it in extremely hot or freezing conditions.

Generally, this means it's better to store a bottle of bleach in a cabinet inside the house, which has a relatively stable room temperature, as opposed to a garage or outside storage shed.

Bleach is sold in an opaque container. Don't switch it out for a clear container because exposure to light will degrade the chemical more quickly.

Like other hazardous chemicals, make sure it's kept away from children and pets. It's also a good idea to store bleach away from other household cleaners because it can react with many of them to release toxic fumes.

Anne Marie Helmenstine, Ph.D.

Introduction

Ph.D. in biomedical sciences from the University of Tennessee at Knoxville - Oak Ridge National Laboratory.

Science educator with experience teaching chemistry, biology, astronomy, and physics at the high school, college, and graduate levels.

ThoughtCo and About Education chemistry expert since 2001.

Widely-published graphic artist, responsible for printable periodic tables and other illustrations used in science.

Experience

Anne Helmenstine, Ph.D. has covered chemistry for ThoughtCo and About Education since 2001, and other sciences since 2013. She taught chemistry, biology, astronomy, and physics at the high school, college, and graduate levels. She has worked as a research scientist and also abstracting and indexing diverse scientific literature for the Department of Energy.

In addition to her work as a science writer, Dr. Helmenstine currently serves as a scientific consultant, specializing in problems requiring an interdisciplinary approach. Previously, she worked as a research scientist and college professor. 

Education

Dr. Helmenstine holds a Ph.D. in biomedical sciences from the University of Tennessee at Knoxville and a B.A. in physics and mathematics with a minor in chemistry from Hastings College. In her doctoral work, Dr. Helmenstine developed ultra-sensitive chemical detection and medical diagnostic tests.

ThoughtCo and Dotdash

ThoughtCo is a premier reference site focusing on expert-created education content. We are one of the top-10 information sites in the world as rated by comScore, a leading Internet measurement company. Every month, more than 13 million readers seek answers to their questions on ThoughtCo.

For more than 20 years, Dotdash brands have been helping people find answers, solve problems, and get inspired. We are one of the top-20 largest content publishers on the Internet according to comScore, and reach more than 30% of the U.S. population monthly. Our brands collectively have won more than 20 industry awards in the last year alone, and recently Dotdash was named Publisher of the Year by Digiday, a leading industry publication.

https://www.thoughtco.com/chlorine-bleach-shelf-life-3976002

CLEAN COAL TECHNOLOGY - Electric companies and businesses with power plants burn coal to make the steam that turns turbines and generates electricity. When coal burns, it releases carbon dioxide and other emissions in flue gas, the billowing clouds you see pouring out of smoke stacks. Some clean coal technologies purify the coal before it burns. Clean coal technology seeks to reduce harsh environmental effects by using multiple technologies to clean coal and contain its emissions. Coal is a fossil fuel composed primarily of carbons and hydrocarbons. Its ingredients help make plastics, tar and fertilizers. One type of coal preparation, coal washing, removes unwanted minerals by mixing crushed coal with a liquid and allowing the impurities to separate and settle. Other systems control the coal burn to minimize emissions of sulfur dioxide, nitrogen oxides and particulates.

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Clean Coal Technology

What is clean coal technology?

BY SARAH DOWDEY

  

Coal is the dirtiest of all fossil fuels. When burned, it produces emissions that contribute to global warming, create acid rain and pollute water.

With all of the hoopla surrounding nuclear energy, hydropower and biofuels, you might be forgiven for thinking that grimy coal is finally on its way out.

But coal is no sooty remnant of the Industrial Revolution -- it generates half of the electricity in the United States and will likely continue to do so as long as it's cheap and plentiful [source: Energy Information Administration]. 

Clean coal technology seeks to reduce harsh environmental effects by using multiple technologies to clean coal and contain its emissions.

Coal is a fossil fuel composed primarily of carbons and hydrocarbons. Its ingredients help make plastics, tar and fertilizers.

A coal derivative, a solidified carbon called coke, melts iron ore and reduces it to create steel. But most coal -- 92 percent of the U.S. supply -- goes into power production [source: Energy Information Administration].

Electric companies and businesses with power plants burn coal to make the steam that turns turbines and generates electricity.

When coal burns, it releases carbon dioxide and other emissions in flue gas, the billowing clouds you see pouring out of smoke stacks.

Some clean coal technologies purify the coal before it burns.

One type of coal preparation, coal washing, removes unwanted minerals by mixing crushed coal with a liquid and allowing the impurities to separate and settle.

Other systems control the coal burn to minimize emissions of sulfur dioxide, nitrogen oxides and particulates. 

Wet scrubbers, or flue gas desulfurization systems, remove sulfur dioxide, a major cause of acid rain, by spraying flue gas with limestone and water. The mixture reacts with the sulfur dioxide to form synthetic gypsum, a component of drywall.

Low-NOx (nitrogen oxide) burners reduce the creation of nitrogen oxides, a cause of ground-level ozone, by restricting oxygen and manipulating the combustion process. 

Electrostatic precipitators remove particulates that aggravate asthma and cause respiratory ailments by charging particles with an electrical field and then capturing them on collection plates.

Gasification avoids burning coal altogether. With integrated gasification combined cycle (IGCC) systems, steam and hot pressurized air or oxygen combine with coal in a reaction that forces carbon molecules apart.

The resulting syngas, a mixture of carbon monoxide and hydrogen, is then cleaned and burned in a gas turbine to make electricity.

The heat energy from the gas turbine also powers a steam turbine. Since IGCC power plants create two forms of energy, they have the potential to reach a fuel efficiency of 50 percent [source: ­U.S. Department of Energy]. ­

Next, we'll learn about the most ambitious of all clean coal technologies and what needs to happen before clean coal can become commercially feasible.

Where do the emissions go?

Carbon capture and storage -- perhaps the most promising clean coal technology -- catches and sequesters carbon dioxide (CO2) emissions from stationary sources like power plants.

Since CO2 contributes to global warming, reducing its release into the atmosphere has become a major international concern. In order to discover the most efficient and economical means of carbon capture, researchers have developed several technologies.

Flue-gas separation removes CO2 with a solvent, strips off the CO2 with steam, and condenses the steam into a concentrated stream.

Flue gas separation renders commercially usable CO2, which helps offset its price.

Another process, oxy-fuel combustion, burns the fuel in pure or enriched oxygen to create a flue gas composed primarily of CO2 and water -- this ­sidesteps the energy-intensive process of separating the CO2 from other flue gasses.

A third technology, pre-combustion capture, removes the CO2 before it's burned as a part of a gasification process.

After capture, secure containers sequester the collected CO2 to prevent or stall its reentry into the atmosphere.

The two storage options, geologic and oceanic, must contain the CO2 until peak emissions subside hundreds of years from now.

Geologic storage involves injecting CO2 into the earth. Depleted oil or gas fields and deep saline aquifers safely contain CO2 while unminable coal seams absorb it.

A process called enhanced oil recovery already uses CO2 to maintain pressure and improve extraction in oil reservoirs.

Ocean storage, a technology still in its early stages, involves injecting liquid CO2 into waters 500 to 3,000 meters deep, where it dissolves under pressure.

However, this method would slightly decrease pH and potentially harm marine habitats.

All forms of CO2 storage require careful preparation and monitoring to avoid creating environmental problems that outweigh the benefits of CO2 containment.

Since alternative forms of energy cannot yet replace a power source as cheap and plentiful as coal, clean coal technology promises to mitigate the increasingly severe climactic effects ­of coal emissions.

Utility companies and businesses do not, however, always accept technology purely for the sake of the environment -- the technology must first make economic sense.

Cleaning coal and sequestering its emissions significantly raises the per-BT­U price of what would otherwise be an inexpensive fuel.

While selling byproducts like gypsum or commercial CO2­ for sodas and dry ice can offset the price of clean coal technologies, a charge on carbon could make emission-reduction financially realistic.

Sarah Dowdey

Contributor — HowStuffWorks

https://science.howstuffworks.com/environmental/green-science/clean-coal.htm

KIRLIAN PHOTOGRAPHY - Accidentally discovered by Mr. and Mrs. Kirlian in 1939, this photographic technique has a long history of association with New Age metaphysics and the theory of “auras”. To this day, a variety of mystical and healing practices label themselves “Kirlian” – even if they have nothing to do with the original photographic technique. Separating the truth of Kirlian photography from the myth is not a simple task; as is so often the case, scientists believe the whole thing has been debunked, while believers are quick to point out flaws in the experiments, while offering scientific sounding explanations of their own. The Kirlian’s themselves suggested that the auras in fact represented the “life force” of the object being photographed. The idea is that all living things emit an invisible aura, which the high voltage charge makes visible to the camera.

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Kirlian Photography

What is Kirlian Photography?

By Daniel Sherwin 

Photography is a photographic technique that involves shooting a high voltage charge through an object that is connected to a photographic plate.

The resulting image typically includes a colored “aura” around the object.

There is perhaps no type of photography so shot through with mystery and rumor as Kirlian Photography.

Accidentally discovered by Mr. and Mrs. Kirlian in 1939, this photographic technique has a long history of association with New Age metaphysics and the theory of “auras”.

To this day, a variety of mystical and healing practices label themselves “Kirlian” – even if they have nothing to do with the original photographic technique.

Separating the truth of Kirlian photography from the myth is not a simple task; as is so often the case, scientists believe the whole thing has been debunked, while believers are quick to point out flaws in the experiments, while offering scientific sounding explanations of their own.

The Kirlian Myth

The Kirlian’s themselves suggested that the auras in fact represented the “life force” of the object being photographed.

The idea is that all living things emit an invisible aura, which the high voltage charge makes visible to the camera.

A couple of well-known experiments involving plant leaves seem to support this theory.

In one, a leaf is photographed over several days as it dies. The aura is large and intense in the first, and grows steadily fainter and its “life force” vanishes.

In another, the leaf is torn and then immediately photographed. The ‘aura’ of the missing section is still visible in the photograph, even though it is no longer physically present.

The Kirlian Myth really took off during the Seventies in the United State, when its peculiar blend of scientific discovery and metaphysical implications captured the attention of New Age practitioners.

It was popularized by a 1970 book called Psychic Discoveries Behind the Iron Curtain (which incidentally won that year’s Most Awesome Title award).

The Psychologist Dr. Thelma Moss of UCLA explored implications of Kirlian effects during that decade. It was in her laboratory that the most famous Kirlian photographs were shot: they appear as the album art of George Harrison’s 1973 album Living in the Material World.

The Counter-Myth

Sadly, for us, we no longer live in the psychedelic seventies, and as a result the credibility of the Kirlian Myth has taken a hit.

Scientists today generally believe that physical phenomena, rather than life forces, best explain the Kirlian effect.

They point out that even inanimate objects appear to have auras, and point to methodological errors in the “torn leaf” experiment.

No one denies that these auras really do appear, but scientists believe that they reveal water molecules surrounding the object. This explains the diminishing aura as the leaf dries out in the first experiment.

Create your own Kirlian Photos!

Even if they don’t give us a glimpse of our immaterial life force, Kirlian photos can still be pretty cool to look at.

Unfortunately, taking them, yourself requires either a specialized camera, or working with sheet metal and a high voltage power source.

If that sounds appealing to you, check out this article . For the rest of us, may I humbly recommend a little bit of photo editing?

Transforming a simple photograph into a mystical masterpiece is a way to flex your PSP muscles. Give it a try yourself, and post the results in the comments to the post. We’d love to see what you can come up with!

The goal of the Discovery Center is simple: to help people pursue their creative interests.

We know that there are two sides to any artistic project, the creative idea and the technical know-how. The Discovery Center therefore aims to inspire and to educate. Think of us as a forum for aspiring enthusiasts to learn new skills and get new ideas in their own way and at their own pace. The site includes a wide variety of creative and instructional content designed to cater to every personality and learning style. You will find new inspiration while browsing galleries of artistic masterpieces from around the world. You can learn at your own pace with structured courses made up of easy-to-follow video tutorials, or enhance your training offline with a variety of detailed written tutorials and eBooks. We want you to learn the way you want, when you want!

Creating is a journey. So is learning. That journey begins here.

https://learn.corel.com/blog/what-is-kirlian-photography/

ACID MINE DRAINAGE - Acid mine drainage mostly occurs where mining is done to extract coal or metals from sulfur-bearing rocks. Silver, gold, copper, zinc, and lead are commonly found in association with metal sulfates, so their extraction can cause acid mine drainage. Rainwater or streams become acidified after they run through the mine’s tailings. In hilly terrain, older coal mines were sometimes built so that gravity would drain out water from inside the mine. Long after those mines are closed, acid mine drainage continues to come out and contaminate waters downstream. In some circumstances, sulfur-bearing rock can be exposed to water in non-mining operations. Drinking water becomes contaminated. Groundwater can be affected, impacting local water wells.

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Acid Mine Drainage

What Is Acid Mine Drainage?

by Frederic Beaudry 

In a nutshell, acid mine drainage is a form of water pollution that happens when rain, runoff, or streams come in contact with rock that is rich in sulfur.

As a result, the water becomes very acidic and damages downstream aquatic ecosystems.

In some regions, it is the most common form of stream and river pollution.

Sulfur-bearing rock, especially one type of mineral called pyrite, is routinely fractured or crushed during coal or metal mining operations, and accumulated in piles of mine tailings.

Pyrite contains iron sulfide which, when in contact with water, dissociates into sulfuric acid and iron.

The sulfuric acid dramatically lowers the pH, and the iron can precipitate and form an orange or red deposit of iron oxide that smothers the bottom of the stream.

Other harmful elements like lead, copper, arsenic, or mercury may also be stripped from the rocks by the acidic water, further contaminating the stream.

Where Does Acid Mine Drainage Happen?

It mostly occurs where mining is done to extract coal or metals from sulfur-bearing rocks.

Silver, gold, copper, zinc, and lead are commonly found in association with metal sulfates, so their extraction can cause acid mine drainage.

Rainwater or streams become acidified after they run through the mine’s tailings.

In hilly terrain, older coal mines were sometimes built so that gravity would drain out water from inside the mine.

Long after those mines are closed, acid mine drainage continues to come out and contaminate waters downstream.

In the coal mining regions of the eastern United States, over 4,000 miles of stream have been impacted by acid mine drainage.

These streams are mostly located in Pennsylvania, West Virginia, and Ohio. In the western U.S., on Forest Service land alone there are over 5,000 miles of affected streams. 

In some circumstances, sulfur-bearing rock can be exposed to water in non-mining operations. For example, when construction equipment cuts a path through bedrock to build a road, pyrite can be broken up and exposed to air and water.

Many geologists thus prefer the term acid rock drainage, since mining is not always involved.

Environmental Effects

·      Drinking water becomes contaminated. Groundwater can be affected, impacting local water wells.

·      Waters with a very low pH can support only severely reduced animal and plant diversity. Fish species are some of the first to disappear. In the most acidic streams, only some specialized bacteria survive.

·      Because of how corrosive it is, acidic stream water damages infrastructure such as culverts, bridges, and stormwater pipes.

·     Any recreational potential (e.g., fishing, swimming) and scenic value for streams or rivers affected by acid mine drainage are greatly reduced. 

Solutions

·     Passive treatment of acidic streams can be conducted by routing the water into a purpose-built wetland designed to buffer the low pH.

Yet, these systems require complex engineering, regular maintenance, and are applicable only when certain conditions are present.

·     Active treatment options include isolating or treating the waste rock to avoid contact of water with sulfates.

Once water has been contaminated, options include pushing it through a permeable reactive barrier that neutralizes the acid or routing it through a specialized wastewater treatment plant.

Frederic Beaudry

Introduction

Associate professor of environmental science at Alfred University in New York

Ph.D. in wildlife ecology from the University of Maine

Experience

Dr. Frederic Beaudry is a former writer for ThoughtCo who contributed articles on pollution, global warming, and climate science for three years. He is an associate professor of environmental science at Alfred University in New York. Prior to teaching, he worked as a wildlife biologist, focusing on the ecology and conservation of birds and turtles. Beaudry has authored several scientific papers on land use and conservation and has conducted research examining land use changes and their effects on bird and amphibian communities.

Education

Beaudry has a B.S. in biology from Université du Québec à Rimouski and an M.A. in natural resources from Humboldt State University. He earned a Ph.D. in wildlife ecology at the University of Maine. Beaudry completed postdoctoral research at the University of Wisconsin-Madison.

ThoughtCo and Dotdash

ThoughtCo is a premier reference site focusing on expert-created education content. We are one of the top-10 information sites in the world as rated by comScore, a leading Internet measurement company. Every month, more than 13 million readers seek answers to their questions on ThoughtCo.

For more than 20 years, Dotdash brands have been helping people find answers, solve problems, and get inspired. We are one of the top-20 largest content publishers on the Internet according to comScore, and reach more than 30% of the U.S. population monthly. Our brands collectively have won more than 20 industry awards in the last year alone, and recently Dotdash was named Publisher of the Year by Digiday, a leading industry publication.

https://www.thoughtco.com/what-is-acid-mine-drainage-1204134