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Pag. 13
Purification and characterization of reagent grade NaCl obtained from
Crucita seawater
Purificación y caracterización de NaCl grado reactivo obtenido del agua de mar de Crucita
Antonella Ferrin
1
* ; Thalía Caicedo
2
; Segundo García
3
; Ramón Cevallos
4
& Ariana García
5
Received: 05/07/2024 – Accepted: 12/10/2024 – Published: 01/01/2025
Research
Articles
X
Review
Articles
Essay
Articles
* Author for correspondence.
Abstract
The main objective of this work is to analyze and apply the processes to obtain sodium chloride (NaCl) in a seawater sample form Crucita-Manabí and
bring it to a higher purity in accordance with the Pharmacopoeia standards of the United States (USP). USP establishes quality standards and specifications
for a wide range of pharmaceutical, chemical and health products. Therefore, the research was developed in three stages: the first corresponded to the
purification of NaCl through the compilation of information from bibliographic sources that allowed investigating the different industrial and artisanal
processes for the purification of NaCl, through this research it was possible to determine that to carry out this process separation, crystallization, distillation
and filtration techniques were applied that allow the elimination of impurities present in the sample. The second stage corresponded to the analysis
established based on the results obtained in the purification process; Therefore, it was essential to evaluate the conditions that allowed the impurities
present to be eliminated, making it necessary to perform physical and chemical tests to determine the percentage of purity of the final product. Finally,
the third stage consisted of analyzing the final product to establish whether it met the proposed objective based on the USP regulations on NaCl.
Keywords
Sodium Chloride, Purification, Crystallization, Distillation, Filtration.
Resumen
El presente trabajo, tiene como objetivo principal analizar y aplicar los procesos para la obtención del cloruro de sodio (NaCl) grado reactivo en muestra
de agua de mar de Crucita-Manabí y llevarlo a una pureza más elevada acorde a los estándares de Farmacopea de los Estados Unidos (USP, por sus siglas
en inglés). La USP establece estándares y especificaciones de calidad para una amplia gama de productos farmacéuticos, químicos y de salud. Por tanto,
la investigación se desarrolló en tres etapas: la primera correspondió a la purificación del NaCl a través de la recopilación de información de fuentes
bibliográficas que permitieron poder analizar los diferentes procesos industriales y artesanales para la purificación del NaCl, mediante esta investigación
se pudo determinar que para llevar a cabo este proceso se aplicaron técnicas de separación, cristalización, destilación y filtración que permiten la
eliminación de impurezas presentes en la muestra. La segunda etapa, correspondió al análisis establecido en base a los resultados obtenidos en el proceso
de purificación; por tanto, fue fundamental evaluar las condiciones que permitieron eliminar las impurezas presentes, siendo necesario realizar pruebas
físicas y químicas para determinar el porcentaje de pureza del producto final. Finalmente, la tercera etapa consistió en analizar el producto final para
establecer si este cumplía con el objetivo propuesto basado en las normativas USP sobre el NaCl.
Palabras clave
Cloruro de Sodio, Purificación, Cristalización, Destilación, Filtración.
1. Introduction
NaCl is a simple chemical compound, composed of a sodium ion (Na+) and a chlorine ion (Cl-), known as common or table salt;
it is a crystalline solid and soluble in water [1].
Reactive sodium chloride is a purified and superior variant of the conventionally used NaCl. This NaCl is used in laboratories
and industries that demand a higher level of purity than that offered by common salt. For its use, reactive NaCl must meet specific
purity requirements (99% - 100.5%) according to USP standards and be free of impurities that could affect the chemical or
biological processes in which it is applied.
This compound has a wide application in sectors such as the chemical and pharmaceutical industry, where it is used as a reagent,
buffering agent and in the production of various chemical products. It is also used in scientific research and in the production of
food, medicines and cosmetics.
The present research focused on obtaining reagent grade NaCl in Ecuador, the purpose was to obtain this product and bring it to
the highest possible purity since the process and purification of this product has not been done before in the country despite
1
Universidad Técnica De Manabí. https://orcid.org/0009-0007-5012-0632 , mferrin4180@utm.edu.ec ; Portoviejo; Ecuador.
2
Universidad Técnica De Manabí. https://orcid.org/0009-0001-7103-9434 , tcaicedo6535@utm.edu.ec ; Portoviejo; Ecuador.
3
Universidad Técnica De Manabí. https://orcid.org/0000-0002-8152-3406 , segundo.garcia@utm.edu.ec ; Portoviejo; Ecuador.
4
Universidad Técnica De Manabí. https://orcid.org/0000-0002-8583-4674 , ramon.cevallos@utm.edu.ec ; Portoviejo; Ecuador.
5
Universidad Técnica De Manabí. https://orcid.org/0000-0001-6893-0843 , agarcia4908@utm.edu.ec ; Portoviejo; Ecuador.
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Pag. 14
having enough raw material available, and to study and analyze the theoretical principles behind the NaCl purification process,
including physical analysis and the chemical reactions involved.
Manabí is a province with saline resources that are used for salt production; however, at present the national industry does not
produce NaCl for reactive use and proof of this is that the country's universities are forced to acquire NaCl in its reactive grade
from chemical companies that import it for use in various analyses or studies carried out in laboratories at the university level.
In this sense, it is necessary to carry out an investigation on the NaCl purification process and analyze it in seawater samples
from Crucita-Manabí to determine its purity level and bring it to a higher purity according to the mentioned standards.
For this, a punctual sampling of the water was carried out in which representative samples were obtained and physical-chemical
analyses were carried out to determine the concentration of NaCl before and after the purification process and then analyze the
purity of the NaCl obtained by the simple evaporation method, evaluating the effectiveness of the process and comparing the
results obtained with the USP standards. The conditions to eliminate the impurities present in the NaCl obtained were evaluated
[1].
2. Materials and methods.
Before the composition of matter was discovered, the word salt referred to any soluble, non-flammable solid, especially when
referring to that which was formed as a result of the evaporation of seawater. Despite its ancient etymology, the word salt is still
used today with two distinct meanings. One is the specific name of the chemical compound sodium chloride, while the other is
the generic name of the group of chemical substances formed from acids in which metals have partially or completely replaced
hydrogen atoms [2]. The salt purification process begins with brine deionization or evaporation, where the ions are treated to
remove impurities and sometimes purified before crystallization. It occurs in open-air salt pans that favor sodium chloride
crystallization when evaporation begins [1].
A new technique to purify sodium chloride is by two-dimensional gel electrophoresis. The technique allows obtaining NaCl
nanoparticles uniform in size and of high purity, which could be used in a variety of areas such as medicine and catalysis [3]. In
the present work, a study was conducted that analyzed how operational parameters affect the purification of NaCl by ultrasound-
assisted crystallization. The results showed that this technique can produce high purity NaCl crystals with lower energy
consumption than conventional techniques [4]. A very novel technique was found to account for the use of modified zeolites as
adsorbents to purify NaCl from wastewater. The technique allowed the recovery of high purity NaCl while reducing the impact
of wastewater effect on the environment [5]. Similarly, purification of reactive NaCl by evaporation, simple distillation and ion
exchange was performed.
The detailed process for obtaining reagent grade NaCl from seawater is described below. The method employed involves a series
of successive stages, including initial physical-chemical analysis, evaporation, recrystallization, dissolution, filtration,
distillation, ion exchange, washing of crystals and finally drying. The NaCl obtained was characterized by physicochemical
analysis to determine purity, reaching a classification that is considered reactive.
The initial sampling and analysis consisted of collecting 20 liters of seawater and performing initial physical and chemical
analyses to determine the characteristics of the seawater. Then, precipitation and primary crystallization were performed, which
consisted of evaporating 12 liters of seawater at 100ºC for 8 hours. Evaporation caused the precipitation of dissolved chemical
compounds, resulting in primary crystallization; 500 ml of distilled water were added to dilute the sample, and then vacuum
filtration was performed to eliminate the non-soluble solids that precipitated as the temperature increased. Next, distillation and
softening were carried out in which a simple distillation was implemented to obtain a concentrated brine which was analyzed
detecting a high hardness in which an ion exchange was applied using a cationic resin to eliminate calcium and magnesium ions.
After this, fractional recrystallization and washing was applied, where the brine was diluted again with 500 ml of distilled water,
evaporated at 100ºC for 10 minutes with constant agitation, the solution was passed through columns of regenerated cationic
resin to eliminate the calcium and magnesium ions (repeated 3 times), Evaporation was carried out to obtain a fractional
recrystallization, the crystals were washed with 500 ml of additional distilled water applying once again a new vacuum distillation
and the evaporation and recrystallization stage was repeated. Finally, the drying and final analysis was carried out, which
consisted of taking the sample obtained to an oven at 105ºC for 5 hours. Once the sample was dry, it was weighed and 562.45 g
of NaCl was obtained, and finally, to determine its percentage of purity, physical-chemical analysis was carried out, where
97.23% of NaCl GR was obtained.
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Fig. 1. Reagent-grade NaCl purification process flow diagram
2.1. Composition of seawater.
Seawater is a solution in water (H_2 O) of many different substances. Up to 2/3 of the natural chemical elements are present in
seawater, although most of them only as traces. Six components, all of them ions, account for more than 99% of the solute
composition [6].
RAW MATERIAL
PROCUREMENT
ANALYSIS
OF THE
SAMPLE
OBTAINED
Yes
CRYSTALLIZATION
WITH
EVAPORATION
No
SAMPLE ANALYSIS
AFTER
CRYSTALLIZATION
DISSOLUTION
AND FILTRATION
GLASS
WASHING
DISSOLUTION
AND SECOND
FILTRATION
DEIONIZATION
WITH CATIONIC
RESIN
ADDITIONAL
PURIFICATION AND
RECRYSTALLIZATION
RECRYSTALLIZATION
PURITY CHECK
WAREHOUSING
EVAPORATED
WATER
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Table 1. Percentage composition of solid solutes in seawater.
Anions
%
Cations
%
Chlorides
55,07
Sodium
30,62
Sulfates
7,72
Magnesium
3,68
Bicarbonates (
)
0,41
Calcium
1,18
Bromide
0,19
Potassium
1,14
Fluorine
0,01
Strontium
0,02
Source: Osorio Arias & Álvarez Silva, 2006.
Information was gathered that allowed us to broaden our knowledge about the different methods and techniques that can be used
in the process of obtaining NaCl Reactive Grade.
2.2. Selection of raw material
The seawater selected for the extraction of NaCl G.R. was collected in the sea of Crucita in the canton of Portoviejo, province
of Manabí, Ecuador (Fig. 1). These samples were transferred to the chemistry laboratory of the Faculty of Engineering and
Applied Sciences.
Fig. 2. Panoramic view of the sea locality of Crucita.
2.3. Experimentation
The experimental work began by taking seawater samples from the parish of Crucita for their respective physical-chemical
characterization in the aforementioned laboratory.
Physical-chemical analysis: alkalinity, chlorides, conductivity, hardness, salinity, total solids, pH and temperature.
Table 2. Physical and chemical analysis of seawater samples.
Components
Results
Units
Alkalinity
96
mg/L
Chlorides
20020
mg/L
Conductivity
64000
us/cm
Hardness
4764
mg/L
Salinity
0,14
%
Total Solids
1380
mg/L
pH
6,27
Temperature
27.5
ºC
The main methods applied during the experimentation were gravimetric and volumetric: in the volumetric method the ion
contained in a given product was determined quantitatively; by measuring the volume of a solution of known concentration or
standard solution that reacts with a known amount of solution containing the element under study and gravimetric method which
is based on the precise and accurate measurement of the mass to be determined, which was separated from the rest of the
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Pag. 17
components of the sample being NaCl. Although most of the substances were found in very low concentration, there were two
important substances that are commercially extracted from seawater: sodium chloride (table salt) and magnesium [7].
The different physical analyses of the water sampled were obtained using the multi-parameter equipment (BLE-9909).
Alkalinity: The alkalinity of seawater plays a crucial role in buffering the pH of the ocean against acidification caused by CO2.
The alkalinity of seawater is mainly determined by two components: carbonate ions and borate ions. These ions neutralize the
hydrogen ions produced by CO2 dissolution, which limits the decrease in pH [8].
Alkalinity consists of the ability to neutralize acids and is the sum of all titratable bases, it prevents water pH levels from
becoming too acidic or basic, giving rise to carbonates and bicarbonates in seawater [9].
Fig. 3. Origen de bicarbonato y carbonato en el ambiente marino.
Hardness: Although seawater is an essential resource for life on earth, its high salinity and hardness prevent it from being used
for human consumption or agricultural irrigation. The removal of salt from seawater, or desalination process, has become an
increasingly important technology. The ability of seawater to dissolve a soap is measured in terms of because of its hardness.
The presence of magnesium and calcium ions is the main cause. The hardness of seawater in the Pacific Ocean ranges from 200
to 400 mg/L CaCO3, with higher values in coastal areas and lower values in the open ocean [10]. Hardness can be temporary or
permanent; the water may contain calcium and magnesium bicarbonate, iron or magnesium. It is characterized because its
softening is achieved by boiling, which consists of the bicarbonate precipitating, releasing carbon dioxide and lowering the pH
value by carbonic acid formations [11].
The analysis of total hardness by titration with EDTA (ethylenediaminetetraacetic acid), allowing the quantification of Ca and
Mg ions and their subsequent conversion to total hardness expressed as CaCO3 was carried out as follows:
10 ml of the sample water was taken in a flask, 1 ml of Buffer solution pH 10 was added and as an indicator a pinch of eriochrome
black T (ENT) was used, the same which is intended to form a purple colored mixture; to proceed to titrate with EDTA; until
the appearance of blue color.
Reactions:
Ca
+2
+ Mg
+2
+ Buffer pH10
Ca
+2
+ Mg
+2
+ ENT (Ca
-
Mg
-
ENT) purpura
(Ca
-
Mg
-
ENT) + EDTA (Ca
-
Mg
-
EDTA) + ENT
During the titration 56.2 ml of 0.01M EDTA were consumed, where 53.5 ml corresponded to MgCO3 and 2.7 ml for CaCO3.
Calcium hardness: With the Buffer pH 10 the total concentration of the sample hardness such as Ca and Mg was determined. To
determine the concentration of calcium present in the sample, 1 ml of Buffer pH 10 was added to the sample and then 20 drops
of KOH were added to regulate the pH 10 to pH 12. From this result, the total hardness was subtracted to obtain the Mg
concentration value.
Consumption = 2,7 ml de EDTA 0,01M en CaCO
3.
Consumption = 53,5 ml de EDTA 0,01M en MgCO
3
.
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Total hardness: 4764 mg/L - Calcium hardness: 270 mg/L= 4494 mg/L of Mg
MgCO3 = 4494 mg/L
It was determined that the hardness present in the sample was found in higher percentage in Mg.
Sulfates (SO4-2): With an average concentration of about 2.7 g/L, sulfate is one of the most present inorganic anions in seawater.
It plays an important role in seawater chemistry and has a major impact on marine life. The complex process of sulfate cycling
in the Pacific Ocean involves a variety of physical, chemical and biological interactions [12]. Sulfates are minerals whose
structural unit is (SO4-2) groups, cations of Al, Na, Ca, K, Mg, Fe, and others can be bonded to sulfates. Among them are
anhydrite and gypsum, which are quite common in the earth's crust [13].
Table 3. Absorbance and concentration data for sulfate
Absorbance
Concentration
280,904
0,481
281,455
0,486
284,789
0,487
Fig. 4. Sulfate ion calibration curve.
The linearity obtained experimentally in the calibration curve for the sulfate ion shows a correlation coefficient r2=0.991 (Fig.
3). The curve was prepared with five concentration levels and a blank in the concentration range 48,000-312,000 ppm.
Chlorides: With an average concentration of about 19.4 g/L, chloride is the most present inorganic anion in seawater. It plays a
fundamental role in seawater chemistry with great impact on marine life. The chloride cycle in the Pacific Ocean is a complex
process involving a series of interactions [14].
Its analysis and concentration determination can be performed by several methods; in the present work, Mohr's method was used,
which involves the quantitative determination of chloride, bromide or cyanide ions by titration with a standard solution of silver
nitrate using Na2CrO4 or K as endpoint chemical indicator [15].
0,48
0,482
0,484
0,486
0,488
280 281 282 283 284 285
Sulfatos
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5 ml was taken and diluted in 95 ml of distilled water; from this dilution, 10 ml was used, 3 drops of K2CrO4 was added as end
point indicator because AgCl is less soluble than Ag2CrO4 since the latter cannot be formed until Cl is fully reacted. There are
three ways to determine the end point of the reaction: when a precipitate is produced, color change and disappearance of turbidity.
When the color change occurred, the titrant AgNO3 made a consumption of 20 ml, then the chloride calculation was performed:
100 ml M ------------ 2,002 g Cl
-1
1000 ml M ----------- x = 20,02 g Cl
-1
Interpretation:
For every 100 ml of sample there was 2.002g Cl-1.
Sodium chloride (NaCl) extraction: Water is a liquid, odorless, colorless and tasteless; it has a bluish tint and can only be detected
in very deep layers. At atmospheric pressure, the freezing point of water is 0°C and the boiling point is 100°C. Water reaches its
maximum density at 4°C and expands as it freezes, thus reducing its density, the same happens when the temperature increases
from 4°C [16].
The evaporation of the water that was applied in the NaCl extraction process was that of the boiling point, in which 12 L of sea
water was evaporated (fig.4); in the course of hours; forming a first crystallization.
Fig. 5. Evaporation process.
Subsequently, NaCl was dissolved in distilled water to separate the insoluble solids that precipitated during the evaporation
process; a vacuum filtration process was applied to this solution.
Vacuum filtration: is an instrumental technique used in laboratories to separate solids from liquids or solutions. This type of
filtration is used when solids are of interest or when gravity filtration is very slow; it is also an essential technique in
recrystallization processes [17].
Recrystallization: is a common purification technique for NaCl, where an impure NaCl solution is dissolved in a suitable solvent,
allowed to evaporate slowly to increase the NaCl concentration and then induce the precipitation of pure crystals. The study of
Li et al. (2023) proposes a new NaCl recrystallization process by controlled evaporation which consists of optimized control
system and optimized vessel design [18]. It was performed by simple distillation (Fig. 5); this is the most widely used procedure
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Pag. 20
for the separation and purification of liquids, and it is the one that is always performed aiming to separate a liquid from its
impurities [19].
Fig. 6. Simple distillation process.
When the first recrystallization was obtained, we proceeded to perform the analysis of chlorides to determine the percentage of
purity of the sample obtained; here we dissolved 0.5 g of sample with humidity in 95 ml of distilled water, obtaining the following
calculation:
100 ml ----------- 8,413g NaCl
1000 ml -----------x = 84,13g NaCl
Obtaining a purity of 84.13% of NaCl.
Ion exchange: According to Degremont (1979), ion exchange is a reversible chemical reaction that takes place when an ion in a
solution is exchanged for another ion of the same sign that is reattached to an immobile solid particle. Ion exchangers are a
process that consists of taking advantage of the ability of resins to exchange ions between a solid phase and a liquid phase in a
reversible way, that is to say that it returns to its original state and without permanent change in the structure of the solid.
Generally, the great usefulness of ion exchange lies in the fact that ion exchange materials can be used over and over again since
the exchanger material can be regenerated as the change it undergoes in the 'operation phase' is not permanent.
Strong acid cationic resin: Although abundant, seawater is not suitable for human consumption or for numerous industrial uses
due to its high concentration of dissolved salts, including Ca and Mg ions, which cause it to have hardness. Ion exchange with
cationic resin has become an effective method to remove these ions, softening seawater and making it useful for a variety of
applications. Seawater contains Ca and Mg, salt-forming salts and increasing the hardness of the water; for this, the cationic resin
of strong acid was used with its abbreviation SAC which is used in the form of sodium (Na), which performs an ion exchange
allowing the hardness of the water produced by Ca and G and when saturated with hardness allows its regeneration with NaCl.
The reaction is as follows:
2R
1
-Na+Ca
2+
R
2
-Ca+2Na
+
2R
1
-Na+Mg
2+
R
2
-Mg+2Na
+
Producing a balance.
The hardness of the water decreased from 39.6 ml of EDTA consumption as a very high hardness; subsequently after the reaction
with the resin the consumption was 2.1 ml of EDTA, presenting high results in the removal of the hardness of our sample:
Hardness without resin:
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At 2.1 ml of 0.01 M EDTA consumption, where the decrease in hardness of the sample water can be seen.
Hardness with resin:
Total hardness: 178 mg/L - Calcium hardness: 10 mg/L= 168 mg/L of Mg.
MgCO3=168 mg/L.
The hardness present in the sample is almost null.
For the analysis of chloride in the sample obtained, the following calculation is analyzed:
100 ml M ------------- 2,432673 g Cl
-1
1000 ml M ------------ x=24,32673 g Cl
-1
Avogadro's law states that “equal volumes react in the same way as long as their concentration is equal”.
Calculation for sodium chloride (NaCl):
Reactions with silver nitrate for the determination of the purity of NaCl by titration of the sample obtained.
NaCl+AgNO
3
=AgCl+NaNO
3
Consumption: 24,3 ml de AgNO
3
3. Results.
Table 4. Final physical-chemical analysis of NaCl obtained from the seawater sample.
Components
Results
Units
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Alkalinity
60
mg/L
Chlorides
24326,73
mg/L
Conductivity
1558
us/cm
Hardness
50
mg/L
Salinity
0,14
%
Total Solids
779
ppm
pH
6,22
Temperature
27.5
ºC
The presence of CaCO3, CaSO4, NaCl, MgSO4, KCl, MgCl2 and MgBr2; indicates that the water sample is mineralized, i.e., it
contains a significant amount of dissolved salts. The initial purity of NaCl in the sample was 84.7314%, which means that there
was a considerable amount of impurities present. The sample was observed to have a high hardness, possibly due to the presence
of calcium and magnesium ions. These ions can have negative effects in various industrial and domestic processes. Ion exchange
with a strong cation resin was effective in removing calcium and magnesium ions, which increased the purity of the NaCl.
Vacuum filtration and recrystallization were performed to obtain purer crystals.
0.0824 g of the NaCl crystals were dissolved in 100 ml of distilled water and the NaCl concentration was calculated, obtaining
a value of 97.23%. The final purity of NaCl, 97.23%, is significantly higher than the initial purity, demonstrating the effectiveness
of the purification process.
The different analyses and techniques used were carried out with the purpose of obtaining the highest degree of purity of NaCl;
and to be able to use it in the laboratories allowing to develop and improve the techniques used for the purification of reagent
grade NaCl decreasing the excessive use of chemicals that can affect the composition of NaCl. Sulfate results were 0.0 in the
final NaCl sample. The market is also driven by the extensive use of NaCl as a raw material in the chemical industry to produce
various chemicals, including chlorine, sodium hydroxide and sodium carbonates. These chemicals have a wide range of
applications, which is further driving the demand for salt.
3.1. Comparison of initial and final analyses.
Table 5. Initial Analysis
Components
Units
Alkalinity
96 mg/L
Chlorides
20020 mg/L
Conductivity
64000 us/cm
Hardness
4764 mg/L
Salinity
0,14%
Total Solids
1380 ppm
pH
6,27
Temperature
27,5 ºC
Table 6. Final Analysis.
Components
Units
Alkalinity
60 mg/L
Chlorides
24326,73 mg/L
Conductivity
1558 us/cm
Hardness
50 mg/L
Salinity
0,14%
Total Solids
779 ppm
pH
6,22
Temperature
27,5 ºC
Universidad de
Guayaquil
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Facultad de
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Ingeniería Química y Desarrollo
Universidad de Guayaquil | Facultad de Ingeniería Química | Telf. +593 4229 2949 | Guayaquil – Ecuador
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Pag. 23
4. Discussion.
The salt market has few formally constituted Ecuadorian companies that share the local market for the supply of all the industrial
and human consumption salts required at the national level, as we can see below:
Table 7. Distribution of the salt market.
Companies
Products
Annual Production
Tons
Participat
ion
%
Average Dollar
Price
Ecuasal C.A.
Cris-Sal
150.000
76%
18.000.000.00
Famosal S.A.
Sea And Salt
12.000
6%
1.440.000.00
Jueza S.A.
Pacific Salt
15.000
8%
1.800.000.00
Proquipil
S.A.
Delisa
20.000
10%
2.400.000.00
Total, Sales And Production In Ecuador
197.000
100%
23.640.000.00
Source: Superintendencias De Compañías. Year 2013 Prepared by: Tammy Rodríguez Balseca.
Fig. 6. Annual Production Tons.
Source: Superintendencia De Compañía. Year 2013 Prepared by: Tammy Rodríguez Balseca.
Artisanal salt production has become a neglected trade because traditional salt producers are unable to compete with the large
production industries established in the market. Faced with such problems, the association of salt producers of Manta, Ecuador
has developed a proposal for a refined salt production process that will contribute to the achievement of this objective. A technical
and operational study is provided which is structured in the following components: product characterization, flow chart of the
salt production process, geographic and micro location, and study of salt production capacities. The aim is for the association of
salt producers to establish a business model to enter the local and national market [22].
NaCl is an important raw material in the chemical industry, since it has several uses. In the laboratory involved in the study,
NaCl is used as raw material to manufacture parenteral solutions, such as: 0.9% NaCl injection and injection of 5% dextrose
with 0.9% NaCl (mixed solution). These solutions are of great importance in the health field, they are used in rehydration
therapies in cases of acute diarrhea and cholera, also for trauma, burns, when patients have a deficit of body Na+ and control the
distribution of water in the organism.
According to the study conducted by Wang et al. (2020), a novel method for purification of reagent grade NaCl is by a
combination of simple distillation and ion exchange membranes. This technique combines the advantages of these methods to
effectively remove impurities such as organic compounds, heavy metals and inorganic salts [23].
It can be stated that the standards for reagent grade NaCl have a percentage of 99% to 100.5% purity both for pharmacopoeia
and those that require even higher percentages such as ISO, however, there are standards that indicate that reagent grade NaCl
can have a minimum of 95% purity, these are usually specific especially in local standards of certain countries which can accept
this minimum level of purity such as the Mexican Official Standard (NOM) and the Ecuadorian Technical Standard (NTE) INEN
1204.
A comparison of NaCl purity standards established by the USP, the Codex Alimentarius and INEN 1234 showed some significant
differences:
76%
10%
6%
8%
ECUASAL
PROQUIPIL
S.A.
FAMOSAL S.A.
JUEZA S.A.
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Pag. 24
The USP indicates that its standards are the most demanding, especially when it comes to the degree of purity, since these grades
are used in applications where high purity and reliability are required, such as in the manufacture of drugs, the minimum purity
grade allowed by the Pharmacopeia is 99.0% [24].
The Codex Alimentarius standards are focused on food safety and establish a purity level that guarantees that the NaCl used in
food does not compromise the health of the consumer; the accepted purity grade is 97.0% as a minimum [25].
INEN 1234, which is a national standard, establishes specific requirements for industrial grade NaCl, which is used in a wide
variety of applications. The required purity level is lower compared to pharmaceutical and food standards in this case it allows
95% purity as a minimum [26].
5. Conclusions.
The initial characterization that was carried out allowed obtaining the values of the different components present in the sample
to be analyzed and to start the present research, with this it was demonstrated that it is possible to obtain reactive grade NaCl
using different techniques and analysis where the use of reagents is not excessively applied, since they change the composition
of the different components found in the sample.
It was possible to obtain reagent grade NaCl from seawater from Crucita-Manabí, Ecuador, with a purity of 97.23%, although it
did not exceed USP international standards (99% - 100.5%), it was demonstrated that it does exceed local standards, which
allows its application. The key finding of this research shows that the seawater from Crucita-Manabí has a chemical composition
suitable for NaCl extraction.
The purification technique used, which combines evaporation, recrystallization and ion exchange, was effective in eliminating
the impurities present in the seawater and obtaining high purity NaCl, which determined that the ion exchange stage with cation
resin was crucial for eliminating calcium and magnesium ions, The final physical-chemical analysis of the NaCl obtained
confirmed that it meets purity standards, which makes it suitable for use in laboratories and industries that demand a high degree
of purity.
The contributions of the present study demonstrate the feasibility of obtaining reagent grade NaCl from Ecuadorian seawater,
which represents a significant contribution to the local industry, since this study can now be replicated to obtain high purity NaCl
from other seawater sources, with potential application in various industries. The results obtained provide valuable information
on the chemical composition of Crucita-Manabí seawater and its potential for NaCl extraction, which can contribute to the
development of new industrial initiatives in the region. The relevance for local industry consists of the great impact of being able
to obtain reactive grade NaCl from Ecuadorian seawater, since it reduces dependence on imports of this product, which translates
into foreign exchange savings for the country. Promote the development of new industries and even existing industries that
require high purity NaCl, such as the pharmaceutical, cosmetic and chemical industries, generating new employment
opportunities in the industrial and scientific sector.
The regulations based on the present research are high quality international regulations; however, there are local regulations in
different countries where a minimum percentage of 95.0% of reagent grade NaCl is allowed, which shows that the 97.23% of
NaCl obtained in the present work can be useful as a reagent use.
In short, this study opens new possibilities for the use of seawater as raw material to obtain reactive grade NaCl, contributing to
the industrial and scientific development of Ecuador.
6.- Author Contributions.
1. Conceptualization: Antonella Ferrin; Ramón Cevallos
2. Data Curation: Thalía Caicedo; Ariana García
3. Formal analysis: Segundo García; Ariana García
4. Acquisition of funds: N/A.
5. Research: Thalía Caicedo; Ramón Cevallos
6. Methodology: Segundo García; Thalía Caicedo
7. Project administration: Antonella Ferrin
8. Resources: N/A.
9. Software: N/A.
10. Supervision: Antonella Ferrin; Ramon Cevallos
11. Validation: Antonella Ferrin; Ariana García
Universidad de
Guayaquil
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ISSN – p: 1390 –9428 / ISSN – e: 3028-8533 / INQUIDE / Vol. 07 / Nº 01
Facultad de
Ingeniería Química
Ingeniería Química y Desarrollo
Universidad de Guayaquil | Facultad de Ingeniería Química | Telf. +593 4229 2949 | Guayaquil – Ecuador
https://revistas.ug.edu.ec/index.php/iqd
Email: inquide@ug.edu.ec | francisco.duquea@ug.edu.ec
Pag. 25
12. Visualization: Thalía Caicedo; Ariana García
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