Waste product of fires

SGB are exported all over the world and different industries with quality first. Our belief is to provide our customers with more and better high value-added products. Let's create a better future together.

Ash or ashes are the solid remnants of fires.[1] Specifically, ash refers to all non-aqueous, non-gaseous residues that remain after something burns. In analytical chemistry, to analyse the mineral and metal content of chemical samples, ash is the non-gaseous, non-liquid residue after complete combustion.

Ashes as the end product of incomplete combustion are mostly mineral, but usually still contain an amount of combustible organic or other oxidizable residues. The best-known type of ash is wood ash, as a product of wood combustion in campfires, fireplaces, etc. The darker the wood ashes, the higher the content of remaining charcoal from incomplete combustion. The ashes are of different types. Some ashes contain natural compounds that make soil fertile. Others have chemical compounds that can be toxic but may break up in soil from chemical changes and microorganism activity.

Like soap, ash is also a disinfecting agent (alkaline).[2] The World Health Organization recommends ash or sand as alternative for handwashing when soap is not available.[3]

Natural occurrence

Ash occurs naturally from any fire that burns vegetation, and may disperse in the soil to fertilise it, or clump under it for long enough to carbonise into coal.

Composition

The composition of the ash varies depending on the product burned and its origin. The "ash content" or "mineral content" of a product is derived its incineration under temperatures ranging from 150 °C (302 °F) to 900 °C (1,650 °F).[4]

Wood and plant matter

The composition of ash derived from wood and other plant matter varies based on plant species, parts of the plants (such as bark, trunk, or young branches with foliage), type of soil, and time of year. The composition of these ashes also differ greatly depending on mode of combustion.

Wood ashes, in addition to residual carbonaceous materials (unconsumed embers, activated carbons impregnated with carbonaceous particles, tars, various gases, etc.), contain a between 20% and 50% calcium in the form of calcium oxide and are generally rich in potassium carbonate. Ashes derived from grasses, and the Gramineae family in particular, are rich in silica.[5] The color of the ash comes from small proportions of inorganic minerals such as iron oxides and manganese. The oxidized metal elements that constitute wood ash are mostly considered alkaline.

For example, ash collected from wood boilers is composed of[6]

The pH of the ash is between 10 and 13, mostly due to the fact that the oxides of calcium, potassium, and sodium are strong bases. Acidic components such as carbon dioxide, phosphoric acid, silicic acid, and sulfuric acid are rarely present and, in the presence of the previously mentioned bases, are generally found in the form of salts, respectively carbonates, phosphates, silicates and sulphates.

Strictly speaking, calcium and potassium salts produce the aforementioned calcium oxide (also known as quicklime) and potassium during the combustion of organic matter. But, in practice, quicklime is only obtained via lime-kiln, and potash (from potassium carbonate) or baking soda (from sodium carbonate) is extracted from the ashes.

Other substances such as sulfur, chlorine, iron or sodium only appear in small quantities. Still others are rarely found in wood, such as aluminum, zinc, and boron. (depending on the trace elements drawn from the soil by the incinerated plants).

Mineral content in ash depends on the species of tree burned, even in the same soil conditions. More chloride is found in conifer trees than broadleaf trees, with seven times as much found in spruces than in oak trees. There is twice as much phosphoric acid in the European aspen than in oaks and twice as much magnesium in elm trees than in the Scotch pine.

Ash composition also varies by which part of the tree was burnt. Silicon and calcium salts are more abundant in bark than in wood, while potassium salts are primarily found in wood. Compositional variation also occurred based on the season in which the tree died.

Specific types

Cremation ashes

Cremation ashes, also called cremated remains or "cremains," are the bodily remains left from cremation.[7] They often take the form of a grey powder resembling coarse sand. While often referred to as ashes, the remains primarily consist of powdered bone fragments due to the cremation process, which eliminates the body's organic materials.[8][9] People often store these ashes in containers like urns, although they are also sometimes buried or scattered in specific locations.[10]

Food ashes

In food processing, mineral and ash content is used to characterize the presence of organic and inorganic components in food for monitoring quality, nutritional quantification and labeling, analyzing microbiological stability, and more.[4] This process can be used to measure minerals like calcium, sodium, potassium, and phosphorus as well as metal content such as lead, mercury, cadmium, and aluminum.

Joss paper ash

Metal contents analysis of ash samples shows that joss paper burning emits a lot of toxic components causing ... There is a significant amount of heavy metals in the dust fume and bottom ash, e.g., aluminium, iron, manganese, copper, lead, zinc and cadmium.[11][12]

&#;Burning of joss paper accounted for up to 42% of the atmospheric rBC [refractory black carbon] mass, higher than traffic (14-17%), crop residue (10-17%), coal (18-20%) during the Hanyi festival in northwest China", according to a study, "the overall air quality can be worsened due to the practice of uncontrolled burning of joss paper during the festival, which is not just confined to the people who do the burning,&#; and &#;burning joss paper during worship activities is common in China and most Asian countries with similar traditions.&#;[13]

Slash-and-burn ash

Wildfire ash

High levels of heavy metals, including lead, arsenic, cadmium, and copper were found in the ash debris following the Californian wildfires. A national clean-up campaign was organised ...[14] In the devastating California Camp Fire () that killed 85 people, lead levels increased by around 50 times in the hours following the fire at a site nearby (Chico). Zinc concentration also increased significantly in Modesto, 150 miles away. Heavy metals such as manganese and calcium were found in numerous California fires as well.[15]

Others

Other Properties

Shape

Size

Hardness

Incomplete combustion

Aging process

Global distillation

Health effects

Mechanism

Oxidative stress

Inflammation

Others

Health conditions

Effect on precipitation

&#;Particles of dust or smoke in the atmosphere are essential for precipitation. These particles, called &#;condensation nuclei,&#; provide a surface for water vapor to condense upon. This helps water droplets gather together and become large enough to fall to the earth&#;[16]

Effect on climate change

See also

References

 Back

Ash Handling Terminology

Ash Handling Terminology and Primer

The ash handling systems of a steam generating plant collect the ash and residue from select points along the boiler flue gas stream (see illustration below), transport it to storage bins or silos, and prepare the ash for transport or disposal. Because ash characteristics are very different from the front of the boiler to the environmental equipment, the collection, transport and storage systems are usually separate for the furnace and collection points downstream.

In a coal-fired boiler, the general categories of ash are:

1. Bottom ash &#; the material that collects at the bottom of the furnace, possibly a heavy slag.
2. Mill rejects &#; the heavy pieces of stone, slate and iron pyrite that are discharged from the coal pulverizer.
3. Economizer ash or popcorn ash &#; the coarse and comparatively dense particles that drop out of the flue gas when the gas changes direction abruptly, such as in the back pass and air heater ducts.
4. Fly ash &#; the fine ash particles that are collected in the particulate control equipment.
5. Scrubber byproduct &#; reacted lime discharged from desulfurization devices.

Ash handling terminology

• Slag &#; Characteristic ash removed from furnace walls
• Bottom ash &#; Ash removed from the bottom of the furnace
• Clinker &#; Large piece of bottom ash that must be broken up before transport
• Fly ash &#; Ash carried by the flue gas into the backpass region and beyond
• Popcorn ash &#; Characteristic ash collected in economizer and air heater hoppers
• Dust &#; Fine ash particulate, typically 50 to 75% of all ash from boiler
• Hydro ejector &#; Venturi device that pulls bottom ash into hydraulic transport system
• Hydrobin® &#; B&W trade name for dewatering bin for removing water from bottom ash
• Hydrovactor &#; Venturi device that provides vacuum source for pneumatic transport
• Airlock valve &#; Two chamber device for feeding ash into higher pressure transport line
• Materials handling valve &#; Valve that admits flyash and air flow into vacuum transport line
• Collector &#; Ash/air separator and transfer tank from vacuum system to silo
• Transporter &#; Flyash collection and aeration vessel for dense phase pneumatic transport
• Vacuum/pressure transfer station &#; Collection and transfer vessel from vacuum line to pressurized line in combination vacuum/pressure pneumatic system
• Drag chain &#; Primary mover in mechanical drag conveyor system
• Flights &#; Attached to drag chain to push ash along stationary platform
• Unloader &#; Device to unload dry ash storage silo into transport vehicles
• Conditioner &#; Adds water to flyash during unloading to minimize airborne dust
• Pugmill &#; One version of combined silo unloader/conditioner

Ash handling principles and applications

Bottom ash

Bottom ash is most commonly conveyed in a hydraulic system in which the ash is entrained in a high flow, circulating water system and delivered to either an ash pond or to a remote dewatering device. Alternatively, mechanical drag systems have been used to convey bottom ash to the dewatering storage bin because they use less water and usually have a lower initial cost. Both systems are designed to handle ash dropping into the conveyance system at temperatures as high as F (C), requiring each system to have a quenching volume of water at the initial collection point (bottom ash hopper).

A more recent development is the completely dry bottom ash conveyor system. This system operates without a quenching volume of water and delivers a dry, lower carbon content material to the discharge end of the conveyor.

Rejects from the pulverizer are typically transported via the bottom ash conveyance system.

Fly ash

Most of the ash from a pulverized coal-fired boiler is carried through the boiler and air heater by the flue gas. As much as 50 to 70% of the ash generated by combustion of pulverized coal is removed from the flue gas by a particulate control device, such as a fabric filter or ESP.

Fabric filters and ESPs have rows of collection hoppers that are emptied regularly by the fly ash transport system. Fly ash consists of fine particles with low density. These particles are rarely transported in a water slurry because they cannot be easily separated from the water at the end of the transport process. For this reason, fly ash is almost always transported pneumatically. Pneumatic transport systems generally fall into four general types:

1. vacuum systems,
2. pressure systems,
3. combination vacuum/pressure systems, or
4. dense phase systems. Once economizer ash is removed from the high temperature gas stream, it can be combined with the pneumatic fly ash transport system.

For more Ash Handling Pump wholesalerinformation, please contact us. We will provide professional answers.