阅读说明：本技术 高温气冷堆燃料元件生产废液的处理方法及处理系统 (Treatment method and treatment system for production waste liquid of high-temperature gas cooled reactor fuel element ) 是由 李林艳 徐建军 程素伟 陈晓彤 刘兵 唐亚平 于 2019-11-21 设计创作，主要内容包括：本公开提供一种高温气冷堆燃料元件生产废液的处理方法和处理系统,该方法包括：将高温气冷堆燃料元件生产废液置于蒸发器中进行蒸发处理,得到蒸汽和残液；蒸汽进行冷凝,得到冷凝液；残液进行固液分离,得到滤液和滤渣,滤渣经干燥后进行煅烧得到煅烧产物；及回收冷凝液和煅烧产物,以用于高温气冷堆燃料元件的生产。该方法由于不需要添加其它药剂,不会带来二次污染问题,且可回收利用绝大部分废液中的有用物质,实现了资源再生利用,具有显著的环境效益和经济效益。(The present disclosure provides a method and a system for treating waste liquid from fuel element production of a high temperature gas cooled reactor, wherein the method comprises: putting the waste liquid of the high-temperature gas cooled reactor fuel element production in an evaporator for evaporation treatment to obtain steam and residual liquid; condensing the steam to obtain condensate; carrying out solid-liquid separation on the residual liquid to obtain filtrate and filter residue, drying the filter residue and calcining to obtain a calcined product; and recovering the condensate and the calcined product for use in the production of the high temperature gas cooled reactor fuel element. The method does not need to add other medicaments, does not bring secondary pollution problem, can recycle most useful substances in the waste liquid, realizes resource recycling, and has remarkable environmental benefit and economic benefit.)

1. A method for treating waste liquid generated in production of high-temperature gas cooled reactor fuel elements comprises the following steps:

putting the waste liquid of the high-temperature gas cooled reactor fuel element production in an evaporator for evaporation treatment to obtain steam and residual liquid;

condensing the steam to obtain condensate;

carrying out solid-liquid separation on the residual liquid to obtain filtrate and filter residue, and drying and calcining the filter residue to obtain a calcined product; and

recovering the condensate and the calcined product for use in the production of the high temperature gas cooled reactor fuel element.

2. The process of claim 1, wherein the filtrate is recycled to the evaporator.

3. The process according to claim 1, characterized in that said evaporation treatment is carried out at a temperature of between 50 ℃ and 95 ℃ and a vacuum of between-0.07 MPa and-0.098 MPa, said condensation temperature being between 0 ℃ and 20 ℃.

4. The processing method of claim 1, further comprising: and when the steam is not completely condensed, introducing the uncondensed steam into an absorption liquid obtained by an absorption device, and recovering the condensate and the absorption liquid for the production of the high-temperature gas-cooled reactor fuel element.

5. A process according to claim 4, wherein water is placed in the absorption unit in an amount of 50-95% by volume of the absorption unit to absorb the uncondensed vapor.

6. The process according to claim 5, characterized in that the absorption liquid is removed and recovered when the mass percentage concentration of ammonia in the absorption liquid is between 15% and 25%.

7. The process of claim 1, wherein the evaporator is a wiped film evaporator and the speed of the wipers is from 50r/min to 250 r/min.

8. The treatment method according to claim 1, characterized in that the filter residue is vacuum dried at a temperature of 60 ℃ to 120 ℃ under a vacuum degree of-0.08 MPa to-0.099 MPa.

9. The process according to claim 1, characterized in that the solid product after drying is calcined at a temperature of 600 ℃ to 900 ℃ for 0.5h to 4.0 h.

10. The treatment method according to claim 1, further comprising absorbing the off-gas generated after the calcination with an alkali solution.

11. A treatment system for production waste liquid of a high-temperature gas cooled reactor fuel element is characterized by comprising:

a feed system;

the liquid inlet of the evaporator is connected with the liquid outlet of the feeding system and is used for evaporating and treating the production waste liquid of the high-temperature gas-cooled reactor fuel element;

the air inlet of the first condensing device is connected with the air outlet of the evaporator and is used for condensing steam obtained after evaporation treatment;

a liquid inlet of the solid-liquid separation device is connected with a liquid outlet of the evaporator and is used for carrying out solid-liquid separation on residual liquid obtained after evaporation treatment; and

the drying device and the calcining device are sequentially connected and are used for treating the filter residue after solid-liquid separation.

12. The treatment system according to claim 11, wherein the solid-liquid separation device further comprises a circulation pipeline connected to the liquid inlet of the feed system to recover the filtrate after the solid-liquid separation.

13. The processing system of claim 11, wherein the evaporator is a wiped film evaporator.

14. The treatment system of claim 11, further comprising an absorption device coupled to said first condensing device to absorb said vapor that is not condensed.

15. The treatment system of claim 11, further comprising an off-gas treatment device comprising a lye, coupled to the calcination device, for absorbing the off-gas generated after the calcination.

16. The treatment system of claim 11, further comprising a second condensing device coupled to the drying device to collect the separated liquid after drying.

Technical Field

The disclosure belongs to the field of radioactive waste liquid treatment, and particularly relates to a treatment method and a treatment system for a high-temperature gas cooled reactor fuel element production waste liquid.

Background

The high temperature gas cooled reactor (HTGR) has the characteristics and advantages of intrinsic safety, versatility, modular construction and the like, so that the HTGR has certain competitiveness and attraction in the international nuclear power market. The basic unit of an HTGR fuel element is an all-ceramic coated particle dispersed in a graphite matrix with the center of the core being the nuclear fuel uranium dioxide (UO)₂) The core is provided with a pyrolytic carbon and silicon carbide coating layer with the thickness of 2-4 layers and different densities. The unique structure of the coating particles prevents radioactive substances from leaking and endangering the public and the environmental safety even under accident conditions, and is an important basis for realizing the inherent safety of the high-temperature gas-cooled nuclear power station.

UO₂The core is the basis of the coating fuel particles and the whole spherical fuel element, and the preparation process is one of the key technologies of the high-temperature gas cooled reactor. At present, the ceramic UO with sphericity, diameter, density and the like completely meeting the design requirements is prepared mainly by adopting an external gel method₂The core mainly comprises dissolving, glue making, dispersion and gelatinization, aging, washing, drying and the like in a wet process, wherein a large amount of waste liquid is generated in the process of dispersing, aging, uranium recovery, washing and other process stages, and the main components of the waste liquid are ammonia water with different concentrations, uranium complex, tetrahydrofurfuryl alcohol (4-HF), ammonium nitrate, polyvinyl alcohol (PVA) and the like.

Along with the commercial development of the high-temperature gas cooled reactor, the production of fuel elements is scaled, if uranium, ammonia water, tetrahydrofurfuryl alcohol and the like can be recycled from production waste liquid, the raw material cost is saved, the discharge amount of waste and the harm of radioactive uranium waste and ammonia nitrogen waste water to the ecological environment are greatly reduced, meanwhile, the complex treatment process of ammonia nitrogen waste water is avoided, and the reliable guarantee is provided for the sustainable development of the high-temperature gas cooled reactor.

At present, there are reports related to the recovery treatment of the waste liquid of the high-temperature gas cooled reactor element core preparation process, for example, chinese patent application No. cn201310144190.x discloses an NH₃-recovery of NThe method adopts a conventional ammonia distillation tower to evaporate, concentrate and recycle ammonia, and the concentration of the ammonia in the treated waste liquid is lower than 1 percent. However, the viscosity of the waste liquid of the core preparation process is high, and the conventional ammonia still is used to cause scaling in the tower, so that kettle removal treatment is required; in addition, the amount of raffinate after treatment is still large and still contains about 0.2% to 1% free ammonia, requiring further treatment to remove radioactive uranium and organic matter.

In order to further treat the radioactive waste liquid remained after the ammonia distillation tower treatment, researchers invented a series of waste liquid treatment methods, for example, chinese patent application CN201310143808.0, etc. adopts microfiltration and ultrafiltration membrane combined filtration method, and combines silica gel adsorption and acid-base neutralization method to treat the waste liquid after ammonia distillation, chinese patent application CN201410546584.2, etc. adopts flocculation precipitation-activated carbon adsorption-silica gel adsorption uranium-reverse osmosis concentration process to treat the waste liquid after ammonia distillation, and chinese patent application CN201710270427.7 adopts neutralization uranium precipitation-complexation uranium precipitation-activated carbon organic matter removal method to treat the waste liquid after ammonia distillation. However, the above methods have problems of poor treatment effect, high treatment cost, and generation of secondary waste liquid, and cannot effectively realize regeneration and reclamation of waste liquid.

Therefore, a new method for treating waste liquid from the production of high temperature gas cooled reactor elements is needed to solve the problems in the prior art.

It is noted that the information disclosed in the foregoing background section is only for enhancement of background understanding of the present disclosure and therefore it may contain information that does not constitute prior art that is known to a person of ordinary skill in the art.

Disclosure of Invention

The main purpose of the present disclosure is to overcome at least one of the above drawbacks of the prior art, and to provide a method and a system for treating waste liquid from the production of high temperature gas cooled reactor elements, which does not cause secondary pollution problems due to no need of adding other chemicals, and can recycle most of useful substances in the waste liquid, thereby achieving resource recycling and having significant environmental and economic benefits.

In order to achieve the purpose, the following technical scheme is adopted in the disclosure:

the invention provides a method for treating production waste liquid of a high-temperature gas cooled reactor fuel element, which comprises the following steps: putting the waste liquid of the high-temperature gas cooled reactor fuel element production in an evaporator for evaporation treatment to obtain steam and residual liquid; condensing the steam to obtain condensate; carrying out solid-liquid separation on the residual liquid to obtain filtrate and filter residue, drying the filter residue and calcining to obtain a calcined product; and recovering the condensate and the calcined product for use in the production of the high temperature gas cooled reactor fuel element.

According to one embodiment of the present disclosure, the filtrate is recycled and introduced into the evaporator.

According to one embodiment of the disclosure, the evaporation treatment is carried out at a temperature of 50 ℃ to 95 ℃ and a vacuum of-0.07 MPa to-0.098 MPa, and the condensation temperature is 0 ℃ to 20 ℃.

According to an embodiment of the present disclosure, further comprising: when the steam is not completely condensed, introducing the uncondensed steam into an absorption device to obtain absorption liquid, and recovering the condensate and the absorption liquid for the production of the high-temperature gas-cooled reactor fuel element.

According to one embodiment of the present disclosure, water is placed in the absorber in an amount of 50% to 95% of the volume of the absorber to absorb uncondensed vapor.

According to one embodiment of the disclosure, the absorption liquid is removed and recovered when the mass percentage concentration of ammonia in the absorption liquid is between 15% and 25%.

According to one embodiment of the present disclosure, the evaporator is a wiped film evaporator with a wiped film speed of 50r/min to 250 r/min.

According to one embodiment of the disclosure, the filter residue is vacuum dried at a temperature of 60 ℃ to 120 ℃ and a vacuum degree of-0.08 MPa to-0.099 MPa.

According to one embodiment of the present disclosure, the dried solid product is calcined at a temperature of 600 ℃ to 900 ℃ for 0.5h to 4.0 h.

According to one embodiment of the present disclosure, the method further comprises absorbing tail gas generated after calcination with alkali liquor.

The present disclosure also provides a system for treating waste liquid from fuel element production in a high temperature gas cooled reactor, comprising: the system comprises a feeding system, an evaporator, a first condensing device, a solid-liquid separation device, a drying device and a calcining device, wherein a liquid inlet of the evaporator is connected with a liquid outlet of the feeding system and is used for evaporating and treating waste liquid generated in the production of the high-temperature gas cooled reactor fuel element; the air inlet of the first condensing device is connected with the air outlet of the evaporator and is used for condensing steam obtained after evaporation treatment; a liquid inlet of the solid-liquid separation device is connected with a liquid outlet of the evaporator and is used for carrying out solid-liquid separation on residual liquid obtained after evaporation treatment; the drying device and the calcining device are sequentially connected and are used for treating filter residues after solid-liquid separation.

According to an embodiment of the present disclosure, the solid-liquid separation device further includes a circulation pipe connected to the liquid inlet of the feeding system to recover the filtrate after the solid-liquid separation.

According to one embodiment of the present disclosure, the evaporator is a wiped film evaporator.

According to an embodiment of the present disclosure, the apparatus further comprises an absorption device connected to the first condensation device to absorb the uncondensed vapor.

According to one embodiment of the disclosure, the device further comprises an exhaust gas treatment device containing alkali liquor, which is connected to the calcining device to absorb exhaust gas generated after calcining.

According to an embodiment of the present disclosure, the drying device further comprises a second condensing device connected to the drying device to collect the liquid separated after drying.

According to the technical scheme, the beneficial effects of the disclosure are as follows:

according to the method, the material composition characteristics of the high-temperature gas cooled reactor fuel element production waste liquid are fully utilized, the method and the system for treating the high-temperature gas cooled reactor fuel element production waste liquid are constructed, other medicament components are not required to be added in the waste liquid treatment process, secondary pollution is avoided, most of ammonia water, uranium, tetrahydrofurfuryl alcohol and other materials in the waste liquid are recycled, waste is greatly reduced, resource recycling is realized, and the method has remarkable environmental benefits and economic benefits.

Drawings

In order that the embodiments of the disclosure may be more readily understood, a more particular description of the disclosure will be rendered by reference to the appended drawings. It should be noted that, in accordance with industry standard practice, various components are not necessarily drawn to scale and are provided for illustrative purposes only. In fact, the dimensions of the various elements may be arbitrarily expanded or reduced for clarity of discussion.

FIG. 1 is a schematic structural diagram of a system for treating waste liquid from fuel element production of a high temperature gas cooled reactor according to an embodiment of the present disclosure;

fig. 2 is a flow chart of a method for treating waste liquid from the production of high temperature gas cooled reactor fuel elements according to an embodiment of the present disclosure.

Wherein the reference numbers are as follows:

100: feeding system

200: evaporator with a heat exchanger

202: residual liquid collecting device

300: first condensing device

400: solid-liquid separation device

500: absorption device

600: drying device

601: condenser

602: condenser receiving tank

700: calcining device

800: tail gas treatment device

Detailed Description

Exemplary embodiments that embody features and advantages of the present disclosure are described in detail below in the specification. It is to be understood that the disclosure is capable of various modifications in various embodiments without departing from the scope of the disclosure, and that the description and drawings are to be regarded as illustrative in nature, and not as restrictive.

In the following description of various exemplary embodiments of the disclosure, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration various exemplary structures, systems, and steps in which aspects of the disclosure may be practiced. It is to be understood that other specific arrangements of parts, structures, example devices, systems, and steps may be utilized, and structural and functional modifications may be made without departing from the scope of the present disclosure. Moreover, although the terms "over," "between," "within," and the like may be used in this specification to describe various example features and elements of the disclosure, these terms are used herein for convenience only, e.g., in accordance with the orientation of the examples described in the figures. Nothing in this specification should be construed as requiring a specific three dimensional orientation of structures in order to fall within the scope of this disclosure.

Referring to fig. 1, a system for treating waste liquid from fuel element production of a high temperature gas cooled reactor according to an exemplary embodiment of the disclosure is representatively shown, and fig. 2 shows a method for treating waste liquid from fuel element production of a high temperature gas cooled reactor according to an exemplary embodiment of the disclosure. The treatment method and system provided by the present disclosure are described by taking the application to the treatment of the waste liquid from the production of the fuel element of the high temperature gas cooled reactor as an example. Those skilled in the art will readily appreciate that many modifications, additions, substitutions, deletions, or other changes may be made to the embodiments described below in order to apply the design associated with the present disclosure to the treatment of waste streams of other similar compositions, and still be within the principles of the high temperature gas cooled reactor fuel cell production waste stream treatment method and system set forth in the present disclosure.

As shown in fig. 1, in the present embodiment, the system for treating waste liquid from the production of high temperature gas cooled reactor fuel elements proposed by the present disclosure mainly includes a feeding system 100, an evaporator 200, a first condensing device 300, a solid-liquid separation device 400, a drying device 600, and a calcining device 700. It should be noted that fig. 1 is only a partial schematic diagram of the processing system, and structures such as motors, valves, and the like are not shown. The structure, connection mode and functional relationship of each main component of an exemplary embodiment of the system for processing waste liquid generated by fuel elements of a high temperature gas cooled reactor proposed by the present disclosure will be described in detail below with reference to the above drawings.

As shown in fig. 1, the system for treating waste liquid from fuel cell production in a high temperature gas cooled reactor includes a feed system 100, and the feed system 100 generally includes a feed tank and a feed pump, wherein the waste liquid from fuel cell production in a high temperature gas cooled reactor is stored in the feed tank and pumped into an evaporator 200 by the feed pump. It should be noted that, the components directly contacting the feed liquid or the gas phase, such as the feeding system 100, the evaporator 200, the first condensing device 300, and the solid-liquid separation device 400, are made of alkali-resistant material with good thermal conductivity, such as 304 stainless steel, 316L stainless steel, 2201 stainless steel, and high borosilicate glass, but the disclosure is not limited thereto. The treated waste liquid produced in the production of the high-temperature gas-cooled reactor fuel element can be aging liquid, cleaning liquid, supernatant, dispersion liquid or a composition thereof and the like of a preparation process of a high-temperature gas-cooled reactor core.

In some embodiments, the feed rate may also need to be controlled based on the amount of waste liquid actually processed. If the feeding is too fast, the temperature of the feed liquid cannot reach the set temperature, the evaporation cannot be performed in time, and most of the feed liquid falls into the residual liquid. On the contrary, if the feeding is too slow, the discharging is also slow, so the optimal feeding speed needs to be adjusted according to the actual condition, the faster evaporation speed is ensured, and the residual liquid can be reduced as much as possible.

Further, the waste liquid from the production of the fuel element of the high temperature gas cooled reactor enters the evaporator 200 through the feeding system 100 for evaporation treatment, and steam and residual liquid are obtained. As shown in FIG. 1, the evaporator 200 is a wiped film evaporator, the evaporator 200 has a residual liquid collecting device 202 below to collect residual liquid remaining after evaporation, and an upper outlet connected to a first condensing device 300 to allow vapor obtained after evaporation to enter the first condensing device 300 for condensation. The first condensing unit 300 includes a double-pass tube condenser and a condensate collecting tank connected therebelow, but the present disclosure is not limited thereto, and other types of condensers may be used.

Specifically, the liquid flowing into the inner wall of the evaporator 200 from the liquid inlet tank is forced to form a film under the action of the rotary scraper, and is efficiently evaporated under the conditions of vacuum and heating, and the ammonia and water with lower boiling points in the waste liquid are gasified to form steam, and then enter the first condensing device 300 to be condensed to obtain condensate which is purer ammonia water. Because the scraper plate continuously rotates and is very close to the inner wall of the evaporator, high-boiling-point components in the waste liquid can not be scaled on the inner wall of the evaporator in the evaporation process, and the smooth proceeding of the thin film evaporation process is ensured.

In some embodiments, the scraper speed during evaporation and condensation is controlled to be 50r/min to 250 r/min. The temperature in the evaporator is controlled at 50-95 ℃, the temperature in the condenser is controlled at 0-20 ℃, and the vacuum degree in the system is controlled at-0.07 MPa to-0.098 MPa, so that the ammonia and water in the waste liquid are vaporized, most of tetrahydrofurfuryl alcohol is difficult to vaporize and is left in the residual liquid, and the condensate is relatively pure ammonia water. Wherein, the heating method can adopt jacket heat-conducting oil heating or steam heating, the vacuum pump can adopt a water ring type vacuum pump unit or a water injection vacuum pump unit, the material adopts 304, 316L stainless steel or 2201 stainless steel, but the disclosure is not limited to this.

In some embodiments, the treatment system further comprises an absorption device 500, the absorption device 500 is connected to the first condensation device 300, as shown in fig. 1, the absorption device 500 is a part of a set of vacuum pumps, and is a circulating water tank and an ammonia absorption device, so as to absorb part of the uncondensed vapor. Deionized water is put into the absorption device in advance, the volume of the deionized water accounts for 50% -95% of the volume of the absorption device, ammonia gas enters the absorption device and then is dissolved in water to obtain ammonia water absorption liquid, and therefore the purpose of collecting residual ammonia is achieved. When ammonia accumulates to a mass fraction of 15% to 25% in absorber 500, it is removed from the absorber and fresh deionized water is replenished. The absorption liquid obtained by the absorption device and the condensate are relatively pure ammonia water which can be recycled for the nuclear UO₂And (5) preparing a process section.

And further, the residual liquid obtained after evaporation enters a solid-liquid separation device 400 for solid-liquid separation to obtain filtrate and filter residue.

With the evaporation process, solid precipitates are obviously separated out from the residual liquid, and particularly, the precipitates are very obvious under the condition that the concentration of free ammonia in the residual liquid is very low. This may be due to: first, in the raw liquid of the waste liquid with high concentration of free ammonia, uranyl ions and ammonia form uranium ammine complex ions ([ UO) with high water solubility₂(NH₃)_x]²⁺) (ii) a In addition, CO in air₂Dissolving in ammonia water to generate CO₃ ^2-Uranyl ion with CO₃ ^2-Combined to generate uranyl tricarbonate complex ion ([ UO)₂(CO₃)₃ ^4-]) (ii) a Along with the evaporation of a large amount of ammonia and water in the waste liquid, the concentration of free ammonia in the concentrated residual liquid is greatly reduced, and the existence form of uranium is converted into ammonium diuranate ((NH) with very low solubility₄)₂U₂O₇) Meanwhile, because the content of water in the concentrated residual liquid is greatly reduced, polyvinyl alcohol and ammonium nitrate in the solution are crystallized and precipitated.

In some embodiments, the solid-liquid separation may be performed by a filter pressing or suction filtration method, so as to separate the solid precipitate from the aqueous solution, thereby obtaining a filtrate and a filter residue. As shown in fig. 1, the solid-liquid separation device 400 further includes a circulation pipeline I, the circulation pipeline I is connected to the liquid inlet of the feeding system 100 to recover the filtrate after the solid-liquid separation, so that the filtrate is combined with the waste liquid stored in the feeding tank, and then evaporation treatment is performed, after multiple times of circulation treatment, about 5% of the residual liquid is difficult to perform membrane evaporation, and the residual liquid is temporarily stored for further separation.

The solid components in the filter residue mainly comprise ammonium nitrate, ammonium diuranate, polyvinyl alcohol, water and tetrahydrofurfuryl alcohol. The filter residue may be further processed using a drying device 600 and a calcining device 700.

In some embodiments, the drying device 600 may be a vacuum drying oven, and the filter residue is dried by vacuum drying to remove the liquid component therein for subsequent calcination. In some embodiments, the drying temperature is 60 ℃ to 120 ℃ and the vacuum degree is-0.08 MPa to-0.099 MPa. In some embodiments, the vacuum pump end of the drying device 600 may be further connected to a second condensing device, which includes a condenser 601 and a condensate receiving tank 602, to collect the separated liquid components after drying, wherein the main components of the liquid components are water and tetrahydrofurfuryl alcohol, which may be combined with about 5% of the residual liquid obtained after evaporation, and further separated and recovered to obtain tetrahydrofurfuryl alcohol.

The dried solid contains ammonium nitrate, ammonium diuranate, and polyvinyl alcohol as main ingredients. After the part of solid is further calcined, optionally, after the part of solid is calcined for 0.5 to 4.0 hours at the temperature of 600 to 900 ℃, ammonium nitrate can be decomposed into N₂O、N₂、NO₂、O₂And H₂Decomposition of O, polyvinyl alcohol to CO₂And H₂Decomposition of ammonium diuranate O into U₃O₈、N₂、NO₂And the like. These gases can be recovered by the tail gas treatment unit 800 connected to the calcination unit 700. Specifically, the exhaust gas treatment device 800 contains an alkali solution, such as a sodium hydroxide solution, which can absorb the exhaust gas generated after the calcination. Most of uranium in the waste liquid is recycled through the calcining process, and the residual solid product after calcining can be returned to the nuclear UO₂The preparation process section of (1) is reused.

In summary, after the treatment system is used for treating the waste liquid generated in the production of the high-temperature gas cooled reactor fuel element, no medicament is added in the waste liquid treatment process except for a small amount of tail gas absorption liquid, so that secondary pollution is avoided; most of ammonia water, uranium and tetrahydrofurfuryl alcohol in the waste liquid can be recycled, so that not only is the volume of waste greatly reduced, but also the resource is recycled, and the method has obvious environmental and economic benefits; in addition, compared with the normal-pressure ammonia distillation process, the treatment method has high evaporation efficiency, and solid dissolved matters in the waste liquid cannot scale on the inner wall of the equipment along with the concentration of the liquid under the action of the rotary scraper, so that the smooth proceeding of the treatment process is ensured.

The present disclosure is further illustrated by the following examples, but is not to be construed as being limited thereby.

The ICP emission spectrometer used below was the Thermo-IRIS Intrared II model.